Aspen Music Festival music director Robert Spano is taking a seat on the piano bench for a virtual performance with violinist Robert McDuffie on Thursday night, closing the Music Fest’s winter series. The pair are frequent musical partners and frequent collaborators, both in Aspen — where McDuffie is an alum and an annual presence at the summer festival — and in Georgia, where Spano also serves as music director of the Atlanta Symphony Orchestra and McDuffie founded the trailblazing Robert McDuffie Center for Strings at Mercer College. The pair recorded Thursday’s performance, featuring Brahms’ first violin sonata and Beethoven’s seventh violin sonata, on campus at Mercer.