to which label did guru's jazzmatazz and moskau sign up ?
SELECT DISTINCT var_uri where brack_open dbr_Guru's_Jazzmatazz,_Vol._4:_The_Hip_Hop_Jazz_Messenger:_Back_to_the_Future dbp_label var_uri sep_dot dbr_Moskau_ attr_open song attr_close dbp_label var_uri brack_close