Well, I was thinking of other artists, like painters, who would get royal commissions or have wealthy patrons. The artists generally lived in squalor nonetheless, but as far as I know, Da Vinci or Mozart didn't have to do anything other than paint or compose. Perhaps teach or perform, but not clean offices at night or work as waiters. Their entire lives were focused on music. Even the jobs that you said Bach held - they were all related to music, did he ever have to work as anything non-music-related?