Atom's top floor is hip-hop with a large number of gaijin (read Americans).
Best bet is to look at metropolice website for listings as the Tokyo scene is always changing.
Here is the LINK...
Listings
And a quick selection for this week.
Club Asia
Massive. Electro, techno: DJs Numanoid, Yoshimasa, etc. From 11pm, ¥3,000 w/1d. Shibuya. Tel: 03-5458-2551.
club asia
Club Why Not?
The Break, Ladies Night. Hip-hop, R&B, reggae. From 7pm, men ¥1,500 w/2d, women free. Yokohama. Tel: 045-663-2955.
www.clubwhynot.com
La Fabrique
Vanity. Electro, rock: DJs Narc, Cash, etc. From 11:30m, ¥3,000 w/1d. Shibuya. Tel: 03-5428-5100.
LA FABRIQUE
Matrix
Matrix Friday. Old school hip-hop, west side, south side, all mix: DJ BeatSniper and more. From 6pm, ¥1,000 (after 11:30pm). Roppongi. Tel: 03-3405-1066.
MATRIX BAR ROPPONGI(
Nuts
Rhythmatism. Hip-hop: DJs Hasebe, Yoshikazu, etc. From 10pm, ¥2,500 w/1d. Shibuya. Tel: 03-5466-8814.
www.clubnuts.net/i&ez
Amrax
Pimp. Techno, electro: DJs Uiroh, Reki, etc. From 5:30am, ¥2,000. Shibuya. Tel: 03-3486-6861.
www.amrax.jp