musings on music and life

April 16, 2012

on digital music archival

Filed under: Uncategorized — sankirnam @ 12:43 pm

Another interest of mine that has developed over the past several years is the collection, digitizing, and archival of classical Carnatic music. This is something I do out of my own interest, for no profit, since a lot of the recordings that I have obtained over the years were obtained at no charge. Similarly, when I share recordings with others, I do not charge them anything. Digital distribution of music, especially Carnatic music, has been dramatically changed by the internet. Since Carnatic music is still a relatively niche art form, it has not been as dramatically affected by Napster and other file sharing services as western mainstream music. Nonetheless, online communities have sprung up dedicated to sharing non-commercial recordings. An example is: http://www.sangeethapriya.org/

Archiving music is not a trivial exercise, however. A lot of the time, concerts are distributed without proper file tagging or artist information. Completing both of these takes time, and deducing the performing artists is not that easy. It takes a trained ear, with lots of experience to do just that (identify the violinist and mrudangist in a recording). I am very good at identifying the percussion artists, and reasonably good at identifying violinists. Even then, this exercise still takes time and careful listening. I have a large number of unlabeled concerts that require such information, and it is difficult to find volunteers who have the skill and time to do this sort of processing. If you are willing to help, let me know. 

The rush in digitizing old music archives also merits discussion. The most popular format used for digital audio storage is .mp3. Mp3 has the advantage in that it is now a near-universal format, even though there are other superior audio codec formats available. The mp3 format is a “lossy” format, in that the file size is compressed from the original. This is achieved by two methods: by using existing file compression methods (like those used in .zip and .rar file formats) and by cutting out bits of the audio file. The latter is actually what contributes most to the reduced size of mp3 files compared .wav or raw audio files. The parts of the audio usually eliminated are frequencies below 50 Hz and above 15 KHz (those outside the range of hearing for most humans). The amount of trimming done to the audio is dictated by the bit rate, with higher bit rates having less audio loss (and correspondingly larger file sizes).

The rush in digitizing music resulted from the fact that analog recordings made on spool tapes or magnetic audio tapes can degrade over time. Therefore, permanent solutions were desired and since mp3 is the most popular format, most audio files are in that format. However, amateur digitizers should be aware (most are not) about the “lossy” nature of mp3. While .mp3 files are fine for casual distribution and listening (listening tests reveal that most people cannot tell the difference between a 128 kbps mp3 and the uncompressed file), digital masters should be saved in a lossless format. While this would entail the necessity of having massive hard drives, declining hard drive prices in recent years are making this more and more practical. The advantage of having lossless master copies is the ability to compress to whatever bitrate is desired without sacrificing too much quality (remember that converting one mp3 to another mp3 results in a further loss of quality – the effects multiply). A tool that allows you to do just that is here: http://www.dbpoweramp.com/dmc.htm

 

Advertisements

Leave a Comment »

No comments yet.

RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Create a free website or blog at WordPress.com.

%d bloggers like this: