A trackmo is not a megademo.
A megademo is composed of a loader with different parts, very often with their own music. A trackmo (the first one was from scoopex in 1990) is used when there is no "break" in the show and the music is never stopped.
To do a trackmo on cpc, you need a loader able to execute others things while it loads data. 
Yes true. But you do not always need great effects while loading... e.g.
good effects (no loading), start loading and switch to more simple effect, when loading is complete switch to better effect, but do this in a seamless way.
music while loading: 5kb demo 3 prooved that more is possible during loading.
I was looking at the disc timings. I worked out that there is some time between sectors (used by gaps, id marks, synchronisation etc), that could be used to make some effects or play music.
You can also use the time during seek too. The problem is the synchronisation of the music... I am looking to add music to my loader (it will be a starkos tune).
The first version of my loader is now ready (no music):
1. a "master maker" program which you use to format disc and to put your files into the special format
2. source code for loader so you can use it in your programs to load the programs put onto the disc.
3. Standard DATA format for track 0 (so you can display graphics with CAT), a different format for other tracks.
I am working on the master maker program so that it will report more errors, and then on the loader so I can use every byte on the disc.
