Every audio CD has a list of tracks with their respective start times, so you can jump to specific songs. The first song also specifies a start time, which does not have to be zero. If it isn’t, the player will skip some of the audio, but you can still reverse back into it.
It’s funny how a CD is more like a tape with contiguous content and an index, rather than a file system.
I bought hundreds of CDs from 1990 through to about 2005, some of them on that list, and I never had a clue about this technique.
I knew about hidden tracks at the end after a silent gap - e.g. Nevermind had a hidden track after 10 minutes of silence at the end, was fun to schedule it on a CD jukebox in a bar...
It's actually more like an analog record than a tape. It's even layout in a spiral (instead of circles, like for a DVD, or like tracks on a floppy or harddisk).
All of them. Audio CDs subdivide tracks with index marks. They are rarely used for general purpose and few hardware or software players expose index navigation now. However, every track has a lead-in at index 0 and the main program at index 1. When you skip tracks you start playback at N.1. You only hear N.0 when playing through from the previous track. There is no limit to what can be in the lead-in and some discs would hide bonus "tracks" in 1.0 which is often skipped over by hardware players but can be manually navigated to with the index buttons.
