Individually, Kronos Quartet and Sun Ra are two of the most groundbreaking names in contemporary music. The former is the legendary San Francisco-based string quartet that laid a blueprint for what concert music could become, working with the likes of John Cage, Tanya Tagaq, and Astor Piazzolla. The latter was a singular jazz and avant-garde bandleader, as well as a philosopher and poet, who honed an extraordinary strain of cosmic experimental music from the 1950s until his ascension in 1993. As a capstone to Kronos Quartet’s 50th anniversary, the group has joined forces with the Red Hot Organization for the new album Outer Spaceways Incorporated: Kronos Quartet & Friends Meet Sun Ra. It’s stacked with some of the most innovative artists active today — everyone from multidimensional electronic musician Jlin, to Moor Mother and DJ Haram’s radical noise / rap project 700 Bliss, to abstract hip hop luminaries Armand Hammer, to avant-garde hero Laurie Anderson, to minimalist pioneer Terry Riley.