Underground hip-hop producers were once measured by whose crates had the rarest old-school vinyl; now, as some of the most revered producers embrace live instruments and rockist song forms, the yardstick seems to be whose album has the most obscure indie-rock cameo. And that’s led to an even more unusual phenomenon: the producer as bandleader. Iconoclast beatmaker Scott Herren, a/k/a Prefuse 73, had enough clout to pull off the dream-team pairing of El-P and Ghostface on his recent Surrounded by Silence (Warp), but the disc is peppered with appearances by the Books, Connecticut noise kid Tyondai Braxton, and Blonde Redhead’s Kazu Makino. Herren is touring with a live band, and his openers include Afro-futurist B-boy Beans, who appears on the disc, and Braxton’s math-rock band Battles. They’re all at the Paradise (617-562-8800) in Boston on Wednesday and at Pearl Street (413-584-7810) in Northampton next Thursday, May 5.

Meanwhile, Cincinnati’s Boom Bip, who’d been lionized for his groundbreaking production on Doseone’s turn-of-the-century disc Clouds, rebelled against his sampler and played lots of actual instruments on his rap-free Blue Eyed in the Red Room (Lex), which includes entrancing vocals by Super Furry Animals’ Gruff Rhys and indie-folk chanteuse Nina Nastasia. Boom is touring with a full-blown live outfit and bringing along former Swirlies drummer Adam Pierce’s indie-pop group Mice Parade as openers. They kick off a tour Sunday at Bar (203-495-8924) in New Haven and then on Monday proceed to T.T. the Bear’s Place (617-492-BEAR) in Cambridge, where Boom will almost cross paths with his pal Dan Snaith. The indietronicist who recorded as Manitoba until a lawsuit by the Dictators’ frontman forced a change to Caribou, Snaith plays the Iron Horse (413-584-0610) in Northampton on Monday and the Middle East (617-864-EAST) in Cambridge on Tuesday behind his new The Milk of Human Kindness (Domino), which he claims was inspired by both Kanye West and Animal Collective.

Not many punk bands can claim to have inspired Fugazi’s Ian MacKaye to become a vegetarian, to have employed Rancid’s Tim Armstrong as a roadie, or to have assisted Green Day drummer Tre Cool in the loss of his virginity, but when you’ve been around as long as hardcore legends MDC — which stands for Millions of Dead Cops, Millions of Damn Christians, and, on their new album, Magnum Dominus Corpus — such honors accrue. They’re at AS220 (401-831-9327) in Providence on Sunday and the Cambridge Elks Lodge (617-354-0404) on Monday. Green Day, meanwhile, play sold-out gigs tonight (April 28) at Cumberland County Civic Center in Portland, Friday at Verizon Wireless Arena in Manchester, and Saturday at the Mullins Center at UMass-Amherst.