I do freelance programming and have pretty bad insomnia, so I have a fairly weird schedule but I do try to keep to it pretty strictly.

I have a time block sheet for the week that functions like university classes with music, work and other things I do. However, my sheet's relative to when I wake up. So I wake up and set the time on my planner which moves all my time blocks to their correct time and I write out a to-do list for what to do that day. Has been working pretty well for me so far.

Every Monday, Wednesday & Friday has a two hour time block dedicated to writing music. ~6 hrs a week of "mandatory" music work which isn't too bad. You get a bit more efficient with the time you do have and if I have spare time, I can do some more on the weekend or something.

I don't think schedules are futile at all, but the main thing I've found is you have to keep at them. If you spend an hour every day writing music, the longer you keep at it the more efficient you'll be. It's kinda Pavlovian. You get used to working at a certain time, your mind gets into the zone a little easier, you learn shortcuts, etc.