‘Crazy Ex-Girlfriend’

Can a show developed for cable (Showtime, specifically) work on a broadcast network? The CW hopes so, especially since this is its only new fall series. “Felicity” fans should find echoes as Rachel Bloom plays Rebecca, who follows a past love interest (Vincent Rodriguez III) from the East Coast to California. Splashy musical numbers enliven the proceedings — as does co-star Donna Lynne Champlin — in the premiere, “Josh Just Happens to Live Here!”