We have some surviving art from the time:

• François Couperin was organist to Louis XIV

• Jean-Baptiste Lully was appointed superintendent of the royal music and music master of the royal family.

• Here's a portrait of several musicians from that period.

Here's a violin player. There are some engravings of events with numerous people, but I am afraid it's difficult to get details from those: Example 1, Example 2, Example 3.

I think some factors might be relevant to creating a mental image of the clothing of the musicians from that time.

Louis XIV used the arts to grow his image and display his power. He influenced all of the arts A LOT, so I assume the image of the musicians was at least given some consideration (even the way people walked, sat down, and stood up was cultivated in some form, they were very committed to style). He employed a very big number of musicians (over a hundred, maybe even close to two hundred), and not all played at the same type of event. There were musicians for religious music, chamber music, outdoors music, ballet, opera...

Hierarchies have been part of organized music for a very long while. The music master would be of higher standing than one of the musicians playing in the back for outdoors music, that might have been reflected in their clothes.

Musicians were servants. Even the ones with important posts were not persons of high social standing.

I hope some of our Art and social historians can help with more details.