Two free drum and bass events are on the SF calendar, and they're running at opposite ends of the venue spectrum. The first is at Underground SF (424 Haight St, Lower Haight) — free, 21+, doors typically at 9pm; check their calendar for the exact date. Luna Assassin headlines alongside a rotating local lineup. The second is at The Midway (900 Marin St, Dogpatch) — also free — and layers in a dance film screening with a 100-watt laser rig, which is a different proposition than a standard club night. BART to 16th/Mission for Underground SF; for The Midway, Caltrain to 22nd gets you closer than BART.

What makes these worth flagging: free DnB in SF usually means a bar night with one DJ and a speaker system borrowed from a dentist's waiting room. Luna Assassin has a consistent following in the Bay Area underground circuit, and The Midway's production setup is legitimate — the laser spec alone suggests someone is treating this as more than a Thursday fill. The dance film component at The Midway is unusual; it's not common to get audio-visual programming alongside a live sound event at that volume.

Practical note for The Midway: the neighborhood is industrial and parking is easier than you'd expect, but it's a dead zone for late-night food. Eat before. For Underground SF, Tornado on Haight is a block away if you want to pre-game with a beer list that will occupy you for longer than you planned.

If you have two hours, hit The Midway early — catch the film element before the floor fills, then stay for the lasers.