Some songs have multiple movements, like allot of classical music as well as some more ambitious rock songs. I would be nice to be able to list those movements in the track field underneath the corresponding track. I will use Rush "2112" for an example:

1. "2112" - 20:34
* "I: Overture" - 4:32
* "II: The Temples of Syrinx" - 2:13
* "III: Discovery" - 3:29
* "IV: Presentation" - 3:42
* "V: Oracle: The Dream" - 2:00
* "VI: Soliloquy" - 2:21
* "VII: Grand Finale" - 2:14
2. "A Passage to Bangkok" - 3:34
3. "The Twilight Zone" - 3:17
4. "Lessons" - 3:51
5. "Tears" - 3:31
6. "Something for Nothing" - 3:59

Also, the total time for each movement should be optional and have no adverse effect on the total track and the albums total time if the times are unknown.