Went here on a Sunday evening around 10pm and had a great night. There were a number of musicians who had turned up to play together and the very relaxed atmosphere of helping yourself to a beer from the fridge and paying at the entrance or running a tab was novel! Would highly recommend a visit for something totally different in Rio.

First, don't show up before 11 or midnight on Friday or Saturday. Artists show up when they feel like since the pay free. It's a dinky little place with a lot of heart that still attracts the old style Samba and Bosa Nova. Edson let's you pay at the end of your stay with out a credit card down...it's a really treat that takes you back in time when Rio was vibrant with young talent and music was everywhere

We lived in Rio 6 weeks and this place became our favorite one. Extremely friendly, best brazilian music (different days - different genres), great owner Alfredo. We found friends here! It's small, only musucians can sit inside but... thats good! All people are close to each other, can speak and sing great bossa nova and samba songs.

My review about Bip Bip (in russian):

<a href="http://aroundprojects.com/2012/12/03/brazil-rio-bar-bip-bip/">Отзыв о баре Бип Бип в Рио-де-Жанейро</a>

I chose to go to Bip Bip on a Wednesday night for 2 reasons: I wanted to experience some live Bossa Nova music, and I'd read, from multiple sources that the music started at 8pm (and I'd rather see something earlier than be waiting for things to start.).
As we were in the area and had nothing more to do we got there just after 7pm, but the place was closed. So we went to a bar a few doors up to wait. Eventually someone arrived at Bip Bip and unlocked, at about 7.30pm.
We went to Bip Bip then too. The drinks system is 'help yourself', pay at the end.
We sat until 9.30, but still there was no sign of the music starting, although a few musicians had arrived and were chatting and drinking out front. We left.
In order to sit down we had to be inside, which was hot. We were told that when the music started we'd have to stand in the street. But, as I mentioned it never strted for us.