‘As many of Weinberg’s works for solo piano have been virtually unknown until recently, by virtue of the fact that this music survived both Nazism and Communism they would merit further investigation. This music has themes to which anyone can relate—to survival in the midst of war and/or oppression, to love, to despair, and to hope. Weinberg’s music richly embodies these, often through the most seemingly simple, folk-like means that continue to engage one’s curiosity’. In this podcast, Allison Brewster Franzetti talks to Gail Wein about the enigmatic composer’s rich piano repertoire.

Album Details…
Catalogue No.: Grand Piano GP610

Vasily Petrenko and the RLPO’s Shostakovich series for Naxos has attracted critical acclaim and numerous plaudits, including ‘Orchestral Recording of the Year’ at the 2011 Gramophone Awards for Symphony No 10.  In this fascinating podcast, Vasily Petrenko talks to Edward Seckerson of The Independent about his relationship with the Shostakovich symphonies and his insights into the great composer’s—and fellow Russian’s—life and work. They also discuss the 10th Symphony, which Petrenko describes as “a perfect piece”, “less extreme than the other symphonies”, but also “very difficult to perform”.

Album Details…
Catalogue No.: 8.572461

Edward Seckerson of The Independent interviews Tony Banks.

Album Details…
Catalogue No.: 8.572986

Edward Seckerson of The Independent interviews Julian Lloyd Webber.

Album Details…
Catalogue No.: 8.572902

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My last post was about the frequencies missing from MP3s.¹

Today, I want to talk about bit rates.

To make sensible decisions about bit rates, it helps to understand a bit about how MP3 encoding works. When your computer makes a CD into an MP3, it has three main ways of making the music take up less space:

1) It throws out sounds you probably can’t hear – either because they’re “masked” by louder sounds, or because they’re only audible to a very small proportion of humans. Done right, this is an elegant exercise in efficiency. Done wrong (or too much) you music sounds tiny, thin and empty.

2) It describes the sound in terms of the shape of the wave, instead of as a big long list of values. If the wave isn’t a very complicated shape, it can do this with virtually no loss of quality.

Here are two MP3s of the same sound – a simple 440Hz sine wave. This is just about the easiest thing to make into an MP3. Although the first file is 10x the size of the second, they sound identical because you don’t even need 16kb to record 1 second of sine wave. Like a stick of rock, the file just says “440hz at -3dBFS” all the way through.

Here it is at 160kbps (mono)

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/Sine-Wave-160kbps.mp3"]

Here it is at 16kbps (mono)

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/Sine-Wave-16kbps.mp3"]

With our nice simple sine wave, there’s no extra data to throw out, so they sound the same. If we give it something really complicated, though, we’ll start to notice a difference.²

Here’s a bit of Debussy’s La Mer³, as a very high quality MP3:

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/La-Mer-Excerpt-320kbps-MP3.mp3"]

That sounds pretty good to me, but here it is again, a tenth of the size:

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/La-Mer-Excerpt-32kbps-MP3.mp3"]

Suddenly it sounds like it’s being played down a telephone. A file this size can happily hold a simple sine wave, but in trying to describe the complex harmony and sonority of Debussy’s orchestration, it has to make some cuts. All the notes are still there, but we’ve lost a lot of what is beautiful about it. When we’re looking for a bit rate that works for us, this is the outcome we’re looking to avoid.

3) Once the fat is trimmed off (1) and the important sounds reduced to their component waves (2), the computer looks for commonly-occuring patterns in what remains, so the information in them only needs to be recorded once.

In our first example above, that means saying “440Hz, -3bDFS” to define the single note, and “ditto” for the rest of the file.

With La Mer, the opportunities are less obvious, but if you see time in 44100ths of a second like the computer does, there’s plenty of repetition here. By itself, this third type of compression is lossless – you get exactly the same data out as you put in, but it takes up less space while being stored.

The combination of these three techniques allow us to make the files much, much smaller. Even the highest-quality MP3s are just a fifth of the size of the original files, but they can be much smaller.

The goal is to find the smallest file size that sounds good to you.

Let’s start with a 16kbps file. At this size, you could fit more than five days of music on a single CD:

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/La-Mer-Short-Excerpt-16kbps.mp3"]

I want you to make up your own mind, but I think you’ll agree that sounded pretty bad. This next one is twice the size, at 32kbps. This would let you put 54 hours of music on a CD.

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/La-Mer-Short-Excerpt-32kbps.mp3"]

This one is twice the size again: 64kbps. You’d get 27 hours of this on one CD.

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/La-Mer-Short-Excerpt-64kbps.mp3"]

Next is 128kbps, or eight times the size we started at. You’d get thirteen and a half hours of this on a CD.

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/La-Mer-Short-Excerpt-128kbps.mp3"]

Double that again, and you’re at sixteen times the size we started at. At 256kbps, you’d get six hours and 47 minutes of music on a CD. The Amazon MP3 store delivers music in this format.⁴

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/La-Mer-Short-Excerpt-256kbps.mp3"]

Finally, the highest bit rate supported by the MP3 format is 320kbps. That’s 20 times the size we started at, and 22% of the size of the original. You’d get about five hours and twenty minutes of this on a CD. If you buy music from ClassicsOnline this is what you’ll get.⁵

[mejsaudio src="http://blog.naxos.com/wp-content/uploads/2012/02/La-Mer-Short-Excerpt-320kbps.mp3"]

You can try all this with your own music, indeed I’d encourage you to. Hook up your computer to your stereo, make some MP3s (and other files), shuffle them up, and try to tell them apart. Remember: bigger is not always better. If you want a fast car, you don’t buy the one that uses the most petrol. You buy the one that goes fastest. If you’re looking for an audio format that sounds good,  don’t go for the one that uses the most data. Go for the one that sounds best, and have fun.

Corrections:

I originally (and wrongly) wrote that the Amazon MP3 store delivered 320kbps files, not 256kbps files. This has now been corrected.

A typo in one of the footnotes said of Variable Bit Rate encoding “there’s no good reason to now use it” which is the exact opposite of what I meant, which is “there’s no good reason to not use it.”

Footnotes:

¹All the files on this page are MP3s. This has become the format of choice for many mainstream download stores (including ClassicsOnline and Amazon) because it works on almost everything. Many of the same basic principles apply to both AAC (used by iTunes) and Ogg Vorbis (used by Spotify). These are both more sophisticated formats that avoid some of the more complex inherent weaknesses of MP3 at the expense of ubiquitous compatibility with all players. In general, either AAC or Ogg Vorbis should sound better than MP3 at a given bit rate, so if getting the best possible sound out of the smallest possible file is a priority for you, I’d suggest you check them out.

²Simple sounds are easier to encode than complicated music, so it tends to be that you only notice that you’re listening to encoded music when something complicated or sudden happens. It’s in these places where the bit rate isn’t high enough. To overcome this, modern MP3 encoders use “variable bit rate” encoding, where a small amount of data is used for the easy bits, and a lot of data is used for the difficult bits. It averages out at the overall target bit rate. I haven’t addressed variable bit rate encoding in the main body of this post because it’s pretty ubiquitous now, and there’s no good reason to not use it.

³This album was produced and engineered by Tim Handley, who has won numerous Grammy awards as a producer.

⁴iTunes also delivers 256kbps files, but in the AAC format¹.

⁵If that doesn’t sound good to you, then you might like to try theclassicalshop.net, eclassical.com or hdtracks.com - all of which will sell you full CD-quality downloads of just about any Naxos record, and many of those from the labels we distribute.

I’ve been putting together a blog post on the way to get the best sound out of MP3s, but there are so many elements to deal with, I thought I’d tackle it in pieces. For this post, I’m just going to talk about the missing frequencies in an MP3.

One of the ways we can fit more music into an MP3 is by discarding the least important information. High frequency sounds have a lot going on very quickly, and they can take up a lot of space, so there’s a lot to be gained from getting rid of them.¹

Still. We don’t want data to be missing. If the range of human hearing is 20-20,000Hz, and everything above 16,000Hz is missing, that feels like a lot. It seems like that would be 20% of the music.

That’s not how frequencies work, though. Every time we go up an octave, the frequency doubles. Going up like this, numbers can get pretty big, pretty fast, and it makes the high frequencies look a lot more important than they really are. If you wanted to make a piano covering the entire range of human hearing², you’d need to give it 120 keys instead of the normal 88. If, halfway through building it, you decided you only wanted it to go up to 10,000Hz, not 20,000Hz, you wouldn’t remove half the keys. You’d only remove 12 of them – seven white ones and five black ones.

In any case, 20,000Hz is the highest anybody can hear, not the highest everybody can hear. Above that, your pets might notice, but you won’t. Our sensitivity to high frequencies deteriorates with age, so for most adults the ceiling is more like 16,000Hz. Your kids can probably hear things you can’t, and your pets can hear things your kids can’t.

If, like me, you’ve spent a lot of time around very loud music, your hearing might top out even lower. I can’t hear much above 13,000Hz.

Try it for yourself: this is a 30-second sweep across the full range of human hearing, from 20hz to 20,000hz. Hit the play button, and listen until it goes quiet: that’s as high as you can hear.³

[If you're reading this in a feed-reader, you might have to scroll to the bottom of the page or visit the site the see the player]

It goes up by 666Hz/Second, so the frequencies are:

Start: 20Hz
1 Second: 686Hz
2 Seconds: 1,352Hz
3 Seconds: 2,018Hz – The highest note in the Queen of the Night’s Aria
4 Seconds: 2,684Hz
5 Seconds: 3,350Hz
6 Seconds: 4,016Hz – The highest note on a piano⁴
7 Seconds: 4,682Hz
8 Seconds: 5,348Hz
9 Seconds: 6014Hz
10 Seconds: 6,680Hz
11 Seconds: 7,346Hz
12 Seconds: 8,012Hz
13 Seconds: 8,678Hz
14 Seconds: 9,344Hz
15 Seconds: 10,010Hz
16 Seconds: 10,678Hz
17 Seconds: 11,342Hz
18 Seconds: 12,008 Hz
19 Seconds: 12,674 Hz
20 Seconds: 13,340Hz – This is where it goes quiet for me ⁵
21 Seconds: 14,006Hz
22 Seconds: 14,672Hz
23 Seconds: 15,338Hz
24 Seconds: 16,004Hz – Very few adults can hear anything above here
25 Seconds: 16,670Hz – A 192kbps MP3 won’t have much above here
26 Seconds: 17,336Hz
27 Seconds: 18,002Hz – A 256kbps MP3 won’t have much above here
28 Seconds: 18,668Hz
29 Seconds: 19,334Hz – A 320kbps MP3 won’t have much above here
30 Seconds: 20,000Hz – Still audible to other animals⁶

There’s an argument that, while these frequencies might be inaudible by themselves, they add character to other sounds in ways that are perceptible to our ears. If this were true, it would be relatively straightforward to prove it and, as far I can see, nobody ever has. It also doesn’t stand up to common sense. Sounds simply don’t become more noticeable when there’s other noises, indeed, the opposite is widely accepted.

So there you go: unless you’re a dog, you can test your hearing and pick and MP3 format that only excludes frequencies you can’t hear. There are, of course, other aspects of MP3 encoding that affect the quality of the sound. Next time, we’ll look at bit rates, fixed and variable, and the effect these have on the sound.

¹The point I wanted to make here is way too nerdy for the first footnote.⁷

²Most notes produced by musical instruments are a combination of several related frequencies, overtones or harmonics. In the piano analogy, I’m only talking about the lowest (and loudest) of these frequencies, called the “fundamental”.

³This is a bit of fun, not a diagnostic tool. If you’re concerned about your hearing, you should see a professional. If you’re interested in playing around with acoustics, though, you should check out the tools at this site. The sound clip on this page is a linear sweep at constant amplitude (-3dBFS). If it seems to get louder and quieter over its range, that’s because your hearing is more sensitive to certain frequencies, (normally around the range of the human voice). This clip is itself encoded as an MP3, but because it contains an extremely simple sound, it doesn’t need to filter out the high frequencies. The MP3 specification is quite flexible on encoding, but all decoders are essentially the same, so I can be confident that your computer will decode the same sound that I get from this file, regardless of the software used to play it back.

⁴The fundamental frequency of the highest note on the piano is 4186.01Hz, but its overtones will extend upwards beyond the limit of human hearing. If you’re interested in this stuff, I’d recommend this video and, if you still want more detail, this one.

⁵I won’t speculate on what happened to the top end of my hearing, but Google Scholar is a good place to explore the considerable research on hearing loss in orchestral musicians.

⁶Dogs can hear up 60,000Hz, mice up to 90,000Hz and bats up to 120,000Hz.

⁷Ok. You’ve been warned. An MP3 describes a complex sound wave in terms of lots of little bits of a sine wave: “At this point, the wave goes up with a bump this tall and this long”. If you want to lose the rest of the day in articles about mathematics on Wikipedia, then it might help you to know that this is called a Fourier Series. The reason I bring all this up is because if you’re encoding music this way, the high frequencies take up a lot of space: at 20Hz, there are 20 wobbles in the line to describe each second of music. At 20,000Hz, there are 20,000 of them. By getting rid of a small number of high frequencies, you can get rid of a very large amount of data. The trick is to find the frequencies you won’t miss.

In this exclusive audio podcast Rutter talks to Edward Seckerson about how a confirmed agnostic became immersed in a world of churches and choral paeans of praise. He recalls his gentle childhood, his doodlings at an old upright piano which was only there because the previous occupants couldn’t get it out of the door. He reflects on why he has never written a musical when his love of the genre and his ear for a good tune dictated he should. And on that note, what it was like to be a tunesmith at a time when it was so deeply unfashionable to be one.

The immensely popular choral composer had his first carol – the Shepherd’s Pipe Carol – published when he was still a teenager and went on to compose more than two dozen others. The royalties got bigger and so did the commissions. His reputation quickly spread Stateside where he still conducts every year at Carnegie Hall in New York. His latest recording for Naxos brings together three large-scale compositions spanning almost two decades. His Gloria was a milestone for him, the first of his pieces to open doors in America. Magnificat is a joyous setting, a kind of Latin American fiesta with “hit” numbers for soprano gently drawing sustenance from the world of musical theatre, and Te Deum springs its own big hymnic surprise at the close.

Album details

Catalogue No. 8.572653

The latest instalment in Vasily Petrenko’s highly acclaimed cycle of the Shostakovich symphonies offers a telling flashback to the composer’s youth.

Symphony No.1 – his sensational symphonic debut – is, according to Petrenko, a whistle-stop tour through revolutionary Petrograd with Shostakovich donning the masks of comedy and tragedy in practical pursuit of his already highly developed sense of irony.

As Petrenko explains to Edward Seckerson, the really big influence here is Stravinsky’s Petrushka, (as witness the devilishly flashy solo piano part) and there is something of the feel of a silent movie in the flickering imagery. Symphony No.3 “The First of May” offers a rather more prescribed view of the Revolution with its brassy choral paean redolent of those striking propaganda posters.

Album Details…
Catalogue No. 8.572396

In 2010 Vasily Petrenko was named Male Artist of the Year at the Classical Brit Awards. His ongoing cycle of the Shostakovich symphonies for Naxos has garnered extraordinary reviews and the latest in the series – the defiant 10th Symphony, regarded by many as the most perfectly balanced of all – represents yet another step forward in this extraordinary symphonic chronicle of Soviet life and times. In this exclusive audio podcast Petrenko talks to Edward Seckerson about the genesis of the cycle in general and the 10th Symphony in particular.

Album details
Catalogue No.: Naxos 8.572461