Who typically commissioned music in the baroque period?

Answer 1

In what period?

Mediaeval to Renaissance music was generally either for the Church or the nobility, though there also roving trobadours who sang for the general public.

The Renaissance saw a big increase in the arts generally, in quality and quantity, with many professional composers retained under a contract form known as "patronage", generally by either royal courts or the Church. The composer would also be working musician, choir-master, music-teacher and generally musical-director for his employer.

From the Baroque onwards, the development of chamber-music published for both professional groups and amateurs meant selling printed scores via music publishers was a steady earner. Mozart apparently had one manuscript rejected by his publisher as being "too difficult for amateurs"! The piece in question survives to be played to this day, albeit probably by professionals.

At around the same time, public performances for their own sake started to appear, and many of the leading composers of the day were very much celebrities - though rather better at their craft than the word implies now it has been cheapened by low-quality TV programmes and associated Press.

As the 19C (late Classical to Romantic) progressed the Church was still important in commisioning music but composers and their agents and publishers were much more free-lance.

Nowadays one of the most important commissioners anywhere of new music is the BBC, both in paying for new compositions and in encouraging talented composers and musicians from around the world. Some music is commissioned for, or at least receives it premiere at, the annual Henry Wood Promenade Concert season held in the Royal Albert Hall but broadcast by the BBC - introducing new music being one of the "Proms'" remits.

A lot of sacred music is also still being written though as far as I know the Church, of any denomination, is no longer a major commissioner.