Who is that masked rapper?

Though iconoclastic master of ceremonies and producer Madlib is the best-known beat scientist at L.A. label Stones Throw Records, it was a man in a metallic hockey mask the crowd wanted Friday at the Henry Fonda Theater, where the L.A. label threw a raucous record-release concert and party.

Madvillain (real name: Daniel Dumile) stepped up to the microphone to a crush of enthusiasm in the last set and spat fierce, tightly controlled raps from his new Madlib-produced album “Madvillainy,” using the mask to differentiate him from his many other recording aliases, including MF Doom, King Geedorah and Viktor Vaughn. The first tune, “Accordion,” featured beats by J-Rocc of the Beat Junkies and a live accordion player, confirming Stones Throw’s off-kilter ethos.

In comparison, the set by Jaylib (Madlib with fellow MC J Dilla) was a rambling collection of choruses and hooks chopped off as soon as they were recognized by the audience. Madlib’s charisma and fun-to-watch staccato delivery are still crowd pleasers, but his constant questions and entreaties for the audience grew tiresome.

Similarly, early DJ sets by Egon and label founder Peanut Butter Wolf completely failed to connect with the large crowd, which stood silent through both performances. Egon focused on mash-ups of jazz instrumentals and Brazilian and French ‘60s pop. Peanut Butter Wolf started with heavy soul and moved into hip-hop.