Jazz Beat: The Bad Plus, with Joshua Redman at the Gem Theater Saturday

The Bad Plus defies categorization — unless the category is “a genre-defying, exploratory jazz trio.” Pianist Ethan Iverson, bassist Reid Anderson and drummer Dave King can claim an oeuvre that includes Nirvana, Ornette Coleman and numerous points between. In 2014, the trio adapted Stravinsky’s Rite of Spring with a challenging mix of tension and grace. The same year, the album Inevitable Western melded the sensibilities of pop and blues with smart jazz rhythms. Joshua Redman — among today’s most influential saxophonists, with a tenor sound that can be lush and lyrical as easily as it can re-juice electric post-bop — first sat in with the Bad Plus in 2011, and last year they released an album together. The Bad Plus Joshua Redman meshes as if these musicians had been a quartet all along, with an inspired and unpredictable adventurousness that challenges the rules of modern jazz.