We don't have synonyms for first act yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are first aid and first fit.
(N) :
a manufacturer of musical instruments and musical learning toys, that produced guitars, bass guitars, guitar and bass accessories, drum sets, percussion instruments, and amplifiers.
(N) :
a manufacturer of musical instruments and musical learning toys, that produced guitars, bass guitars, guitar and bass accessories, drum sets, percussion instruments, and amplifiers.