Jem Aswad Senior Music EditorVeteran Russian musical collective and activists Pussy Riot will be joined by some high-profile guests for their forthcoming concert at Los Angeles’ El Rey Theater on Wednesday: comic Sarah Silverman will be performing a full set, while Big Freedia — fresh from her prominent guest spot on Beyonce’s “Break My Soul” — Salem Ilese, Josiah, Boyfriend, Slayyyter and Eva Elfie will be making special guest appearances, along with previously announced artist Rei Ami.The appearance is a rare high-profile slot for Silverman, who has been keeping a relatively low profile in recent months. Big Freedia and Salem Ilese both appear on Pussy Riot’s “Matriarchy” mixtape, which dropped on Friday. Ilese also released the viral hit “Crypto Boy,” and for which the group’s Nadya Tolokonnikova created the single artwork.