I'd like to start making music on the MSX1 with the build in sound chip with the help of a composer application. PSG Tracker seems to be a good choice, but I cannot find any manual or tutorial on how to use it. E.g. I cannot figure out how to make patterns and how to compose the patterns into a song. And is there a way to export the song to basic or asm?
If you're okay with composing music on a modern computer in stead of the MSX: I personally chose Arkos Tracker 2 because it's cross platform (I'm on a Mac, most trackers are for Windows), and because it's pretty well documented and simple to use. It also comes with a bunch of replayers, also for Z80 (which may need some work depending on the music). But from a user perspective I really like it.
And although you are specifically saying you want to compose for the PSG on an MSX1, maybe you want to compose for OPLL on a SG-1000 Mark III computer. Then better use deflemask
