pattern tracks would be 17-24 since they are accompaniment tracks, running alongside the 16 songtracks. - consider the song mode, where you set up patterns to play along with your 16 song tracks.
in practice, at least in terms of assigned voices, they are running overlaid onto the sets assigned to them: 1-8/9-16. this is my interpretation anyway since i'm of the school that believes that a midi bus only has 16 channels. (someone should do a test: basic pattern, and then do something on each of the 16 song parts.) Eric will come up strong for 1-24 midi channels, because he delved into the sysex, and each has a different address there apparently.
go through all the Jobs in both Pattern and Song and you'll find a lot of correlation; i think the main difference is get phrase/put phrase which is a useful interchange between the two modes, where you can grab a bit of 'song track' and make a Phrase from it, in your Style, or conversely drop sections of patterns into a song. as for the Jobs Menu, it's split into sections; navigate those as headers when you can/have presence of mind to do so.
