Other
Making Internet Audio Files for the Macintosh
A tutorial on making Internet audio files for the Macintosh.
Wikimedia
Wikipedia: Real Audio
Encyclopedia entry that defines the Real Audio format and explains how and why it was created. Links to related information are available as well.
Wikimedia
Wikipedia: Wav
Encyclopedia entry that defines WAV (or WAVE), short for WAVEform audio format, and explains how and why it was created. Links to related information are available as well.
Other
History of Rock and Roll: Technology
This site offers a history of audio formats. Follow the links and learn about the 45 RPM, 33 RPM, and the jukebox.