One of Lapa's classic bohemian spots, this tiny bar in a battered part of the neighborhood has excellent live groups playing to a samba-loving crowd. The outdoor seating and informal setting are an unbeatable mix. Friendly owner Márcio Pacheco hails from Minas Gerais; to get the night started, ask him for a fiery cachaça (high-proof sugarcane alcohol) from his home state.
There's live music most nights starting at 8pm (from 5pm Sunday). Beco do Rato, incidentally, means 'Alley of the Rat'.