Over the weekend, the hip-hop artist Mos Def joined the Brooklyn Philharmonic for a performance in the Bed-Stuy neighborhood of Brooklyn. Above is a video excerpt of their rendition of Frederic Rzewski's Coming Together. Mos Def will appear again with the orchestra tonight at the World Financial Center Winter Garden, in WNYC's New Sounds Live series; Q2 will stream.... The singular English composer Jonathan Harvey, who has long blended high-tech modernist methods with a strong inclination toward religious mysticism, is the focus of two far-flung events in the next two days. Tonight players from the St. Louis Symphony will present an all-Harvey program, as part of the Pulitzer Foundation for the Arts series. Tomorrow night the Berlin Philharmonic will give the premiere of Harvey's Weltethos, a monumental choral-orchestral work with a libretto by the great Swiss theologian Hans Küng.... Gabriel Kahane, whose new album Where Are the Arms is sounding lovelier by the day, performs with the Calder Quartet tomorrow at Largo in L.A.... On Oct. 21-23, An Die Musik in Baltimore will host the Baltimore Lieder Weekend, a series of concerts on the theme of "The Birth of the Lied." Schubert scholar Deen Larsen presides.... Earlier this year I wrote about the excellent Boston-based choir Blue Heron. On Oct. 15 and 16, in Cambridge and New York, they will present a sixteenth-century English and Spanish program in collaboration with Ensemble Plus Ultra, whose ten-CD tribute to Victoria is out now from DG.... There's a Bernard Herrmann festival at Film Forum, starting Oct. 21.... A potentially significant premiere at the LA Phil on Oct. 20: Magnetar, a new concerto for electric cello by the bold young Mexican composer Enrico Chapela. The work takes its title from a rare kind of pulsar that possesses an immensely strong electromagnetic field.