Storing music digitally is full of tradeoffs. The original MP3 format (sometimes referred to as a "codec") was intended to be "good enough," so that you could squeeze a lot of music into a small space and have it sound pretty good. It does so by compressing the information, decreasing the dynamic range, stripping out the nuances, and removing much of the complexity in sound. It is great as an accompaniment while jogging with a headset, but a poor substitute for a CD on a decent stereo system.
There are numerous refinements to this efficient approach that may make the resulting playback less bad, but it still not provide high fidelity. One very disturbing trend I have seen is that of recordings engineered with this loss of sound resolution in mind, resulting in music with an inherently compressed dynamic range. Likewise, if you buy your music over the Internet, you are probably getting it in such a compromised format. I guess if you play everything at one volume, and especially if you keep that volume high and force it down your ear with headphones, you are going to lose your hearing anyway and it will be a moot point. What a vicious cycle!
Polarization seems to be the way of all things, political, religious, technical, ... you name it. The audio world seems to becoming polarized between two extremes of quality. I guess I'm somewhere in the middle: sound quality does matter. Well, maybe I'm on the higher side of the middle...
Sound on CDs is recorded using a standard referred to as "Red Book" (this, incidentally, is what limits CDs to 79.8 minutes of time!) An equivalent, but not identical format on a computer disk is "WAV." Neither are very efficient in terms of storage space. Space can be saved by employing compression, and there are two kinds of audio compression: "lossy," which throws away information as a compromise, and "lossless," which essentially throws away redundant information, so that the original can be reconstructed.
Lossy compression is still favored by many because you can squeeze in a lot more music into a (relatively) small space. The lossy compression Apple favors for the iPod, AAC, has become very popular. Therein lies the problem: much better than the early MP3, you are still ultimately cheating your ears and limiting your options for future sound reproduction.
There are are a couple of choices for lossless compression: FLAC and Apple Lossless (ALAC). FLAC, in particular, seems to have gained support outside of Apple, probably because it is an open, published standard, without any licensing associated with it. The ALAC standard has apparently never been publicly released by Apple, but clever engineers have long since reverse engineered it; it doesn't appear that Apple intends to license it, but nothing stops them from changing it in the future. How does one choose which one to embrace?
FLAC was originally the preferred format for makers of wireless streaming hardware, such as Logitech (formerly Slimdevices) and Sonos. Just one problem: the premier software for creating and managing digital audio libraries is Apple's iTunes, which ignores FLAC. Because they are both lossless, conversions between the two are possible without any loss of sound information.
Consequently, if you use a Mac or PC, it is pretty easy to choose: using ALAC on iTunes gives a powerful and free tool. Should that ever change, one can convert back to FLAC. Whatever you do, don't throw the sound away.
