Conversation so far:
How was the musician Usher interested in art and feminism?
In December 2014, the musician Usher attended and participated in an art installation at JJ Brine's VECTOR Gallery at Select Fair by performance artist Lena Marquise Body As Commodity.
How did the musician Usher participate in the art installation at JJ Brine's VECTOR Gallery at Select Fair by performance artist Lena Marquise Body As Commodity?
Musician Usher did not disclose of the reasons behind his participation: media speculations assumed it was related to art and feminism amid the release of single I Don't Mind.
What album did that single I Don't Mind by the musician Usher come from?
I Don't Mind was released as the intended lead single from the musician Usher's then-upcoming eighth studio album, Hard II Love.
How else did the musician Usher support feminism through art besides participating in the art installation at JJ Brine's VECTOR Gallery at Select Fair by performance artist Lena Marquise Body As Commodity?
Musician Usher is an art collector.

Question: What medium of art does he collect?
Self-contained rewrite: What medium of art does the musician Usher collect?