There’s a rumor circulating, saying that compression ruins classical music. This idea is especially common among audiophiles and hardcore fans of classical music, who turn up their noses at the idea of using MP3 files, and therefore shun the iPod and iTunes. Talk to a dozen classical music fans, and the majority will tell you that they won’t listen to compressed music and don’t want to use an iPod. They think these technologies destroy the quality of the music, and are only good for the raucous music that “others” listen to.
Alas, like many rumors, this one is false. Classical music fans who take the time to explore the iPod and iTunes will find that they’ve been missing something that can change the way they listen to music. While most people use the iPod when commuting, walking, jogging or biking—activities that are generally not conducive to listening to Mahler’s 3rd Symphony—there are still reasons why classical music lovers should look at the iPod.
The iPod is useful for more than just listening to music on the go. I use two 40 GB iPods to store a good part of my 3000-CD music collection, and when I listen to music, I just connect one of them to my stereo. No more looking for CDs, worrying about storing them accessibly, and especially no more having to change CDs for works that span more than one disc. Once I buy a new CD, I import it into iTunes, then put it on one of my iPods.
Much of my music is classical and jazz, and while I was skeptical at first, I’ve found the right way to compress music to make it sound good, as well as the best way to manage classical music in iTunes and on my iPods. (While I’ll mostly talk about classical music in this article, I mean it to include jazz and any other music where sound quality is more important than for, say, pop, rock or rap.)
First of all, compression is not, in and of itself, a bad thing. What can make compressed music sound bad is the type of compression format and bit rate used. Most compression formats used for music are “lossy” compression; this means that the compression algorithm removes data from the original music files to create the compressed versions. When you create a compressed music file at 128 kbps (or 128,000 bits per second), you are reducing it to less than one-tenth its original size. (A raw music file on CD is 1411 kbps.) While some of the space is saved by eliminating redundancy, most of it is due to a simple deletion of non-essential musical information. In short, the music is filtered by the compression tool, and some of the music is removed.
But this is not as bad as it sounds. First, human ears can’t hear anywhere near the entire spectrum of sounds that musical instruments produce. While the perfect ear should be able to hear from 20 to 20,000 Hz, most people’s ears aren’t that sensitive. (Want to check your hearing? You can do so here. In addition, the sounds you hear depend on the environment, whether it is quiet or noisy, and your audio equipment. Even the best audio equipment won’t allow you to hear everything up to 20,000 Hz in a normal room with some ambient noise.
To get the best quality when compressing your files, you need to consider two variables: the type of compression used (or the compression format) and the bit rate. For the former, you have several options with iTunes: AAC, MP3, WAV, AIFF, and Apple Lossless.
Let’s look at the last three formats first, since they result in perfect sounding music. WAV and AIFF are just two types of files that contain the exact same music as the original; when you insert a CD into your computer, it contains WAV or AIFF files (WAV and AIFF are just two different wrappers for native audio files on CDs). You can import CDs in these formats, which do not compress the music at all, but they take up a lot of space. For example, a recording of Ralph Vaughan-Williams’ A Sea Symphony, which lasts 69:45, takes up 704.2 MB on the CD. If you import CDs in WAV or AIFF format, you won’t get much music on your iPod.
The next format to consider is Apple Lossless. As its name suggests, this format removes none of the original data from the music, but merely compresses that data, much the way zip compression compresses files and applications. When you import music in this format, you’ll use much less space than WAV or AIFF, but it still takes up a big chunk of your hard disk: using the same example as above, A Sea Symphony, this takes up 299 MB in Apple Lossless format, a saving of more than 57%. The space taken by Apple Lossless files varies according to the music; even in this symphony, the difference is large: the bit rates for the different movements range from 465 to 725 kbps. (When you import files using Apple Lossless, the bit rate is the result of the compression, so it varies according to the type and density of the music.)
Nevertheless, you’ll still use up your iPod’s disk space very quickly with lossless files; at 4.3 MB per minute (for this specific symphony), you’ll get about 225 hours of music on a 60 GB iPod photo (with no photos).
So now we come to MP3 and AAC files. These are lossy compression formats, which do not render all of the original music when you play them back. Some vendors claim that a 96 kbps MP3 file is “CD quality”. Let’s be clear: it is not. Even a 128 kbps MP3 file doesn’t sound as good as a CD.
At the same bit rate, AAC files sound better than MP3 files. Apple uses 128 kbps AAC as its default importing setting; this sounds about as good as a 160 kbps MP3 file. While this setting is appropriate for some music, and some listeners, it’s not ideal for classical music. I’ve experimented with different bit rates and formats, and, even on very good stereo equipment, I find that 160 kbps AAC files sound excellent; certainly good enough for my ears. If you want to use MP3 files, you should go to at least 192 kbps.
But why stop there? If you don’t think this is good enough, or if your audio equipment is such that you hear the difference between this rate of compression and original CDs, go to the maximum bit rate for AAC or MP3 files: you can go up to 320 kbps, and I defy anyone (in a blind test) to be able to tell the difference between files compressed at this bit rate and original CDs. At this bit rate, your music takes up 139 MB per hour, so you can count on more than 400 hours of music on a 60 GB iPod.
One problem with just about every portable audio player, including the iPod, is that they cannot play music without gaps between the tracks. For most music this is not a problem, but for a lot of classical music, especially operas, this is a deal-breaker. Even the half-second gap between a recitative and an aria is enough to ruin the effect of Handel’s greatest works for the stage.
There is a way around this; it’s not perfect, but it allows you to listen to long works without gaps. When you insert a CD to import your music, iTunes displays all the tracks on the CD. If you select all these tracks (Edit > Select All), you can then join the tracks into a single, long music file.
Select Advanced > Join CD Tracks to do this; iTunes then displays the tracks with a vertical bar indicating that they are joined.
Next, click the Import button to import the CD as a single track.
You don’t have to do this for an entire CD; say you want to import a string quartet as a single track, but the CD contains two quartets. Select the tracks for the first quartet, then join them. You can do the same for the second quartet, having your two string quartets as two tracks, each one containing an entire work.
Joining tracks for multi-movement works can be a good way to manage your listening as well. When you do this, you can more easily make smart playlists that call up entire works; something you cannot do otherwise. You could make a playlist that fills with all your string quartets, all your piano sonatas, or all your symphonies. As long as each one is a single track, you won’t hear movements out of order. However, you lose the ability to listen to individual movements or arias.
A problem arises, however, if you’ve purchased music from the iTunes Music Store, or if you’ve already ripped your CDs as individual tracks and don’t want to rip them again. There are several solutions, depending on your platform and the type of file.
So, classical music fans, you no longer have an excuse: join the digital music revolution. You’ll find out how wonderful it can be to carry around on your iPod all of your favorite music, and listen to it wherever you want.
Kirk McElhearn is the author of several books including iPod & iTunes Garage. His blog, Kirkville features articles about the iPod, iTunes, Mac OS X and much more.