You remember a song from a favourite record, but the track list offers only a medley title. One track can contain several named pieces. A collection index becomes more useful when it can find those pieces without pretending the disc has extra tracks.
Preserve the printed track entry
Keep the track number and title exactly as your copy presents them. Add a separate “includes” field for component titles explicitly listed in the booklet. That gives you one track record with several searchable names rather than several invented track numbers.
For a hypothetical example, track four might be “Evening Medley,” with “Lantern Walk” and “Homeward” listed underneath. The invented titles demonstrate the structure; they are not a claim about a released recording.
Distinguish credits from listening guesses
If you recognise another tune by ear, place it in an observation field until you can verify it. A short quotation of a melody is not automatically a separately credited work. Likewise, an unfamiliar transition does not prove that the printed list is incomplete.
Add a listening route when useful
You may record an approximate playback time for the section you want to revisit, along with the edition or file used. Do not assume the same timing applies to every performance or release. A note such as “second named section, after the quiet transition” can remain useful when timings differ.
This is a different problem from numbering a multi-disc album: it concerns several musical titles inside one track boundary. Keeping those levels separate helps you find the music you remember while preserving the structure of the object on your shelf.