Each sector has 2048 bytes. 72 minutes capacity

A CD-DA sector can contain 2352 bytes of audio data. The sectors are played at a speed of 75 sectors/sec and every sector contains 784 bytes EDC/ECC as well as 98 control bytes. A CD-DA has a basic logical structure and can be divided into a maximum of 99 tracks, each one corresponding to a song. At the beginning of the disc there is a table of contents indicating each track location.

http://uranus.ee.auth.gr/report/eng/part1/chapt-03/3-2-1.html CD structure http://www.cdhome.com.tw/support/cdrfaq.html