A few weeks ago, I received a letter complaining that I gave too much lip service to the big guns (you know who you are) and didn’t focus enough on the underground. OK, you called it. This one goes out to the little guys. And, make a note: all three are free, free, free, (my favorite thing).

Proving once again that you don’t have to be a superclub to book superstars, Halcyon brings two of the city’s best DJs to its fine cafe/record store/hangout joint. Rendezvous and DJ Dinky specialize in robot voices and weird future sonic wizardry of the techno and electro persuasion-plus, there’s two live P.A. from fellow electro fanatics, Informer. Best of all, it’s free, and there won’t be any lines or obnoxious bouncers. Saturday @ 9, Halcyon, 227 Smith, Brooklyn, 718-260-9299.

Scatalogics, which may be the longest open turntable event going, turns three this week. Promoter Ulysses celebrates his third year with Adam Goldstone, the ex-Sleaze Factor tech-house-all-the-time jock, who’s also produced a few bits for the esteemed label Nuphonic Records. You should hope that the free-for-all that precedes Mr. Goldstone is not cringe-inducing. Note to bedroom DJs: Get there early for sign-up. Monday @ 9, Rivertown Lounge, 187 Orchard, 388-1288.

If you don’t get a slot at Scatalogics, there’s a new game in town, called, appropriately, Bedroom DJ Night, The folks who run it offer little info besides the admonishment: “Go to your room,” and the website simply gives the date for the next party. Thanks, guys, big help! But gotta say, nice flyer. Wednesdays @ 9, Bar-B, 188-A Allen, no phone.