Elm City Guitar Quartet +3, Crash (nhic-records.com). This improv jam among four guitarists — Jeff Cedrone, Tom Gogola, Bob Gorry and Christopher Venter, a group that grew out of the New Haven Improvisers Collective — was recorded live at cozy Never Ending Books on State Street one winter's night last December. It's not just four guitarists, though. Sometimes there are drums or an accordion, a saxophone or clarinet. If you think it'd be difficult to improvise quality music cohesively with so many instruments playing at once, you'd be correct. The main thing here is establishing a vibe and then making sure that, given all the freedom in the world to mess around, each of the players somehow keeps that central vibe going. More often than not it sounds like an album of haunted house scary noises ('tis the season), but there is a certain vitality to these recordings that can only be achieved when a group of musicians commit to diving way into the deep end and seeing where it leads.

New Haven Improvisers Collective, featuring members of Elm City Guitar Quartet +3, plays Nov. 7 at Firehouse 12.

Closely Watched Trains (self-titled, myspace.com/closelywatchedtrainscwt). Closely Watched Trains do a few different things well. They open this CD with a short, down-home front-porch instrumental Americana jam, and then segue immediately into a rocker of sorts, "Night to Shine," with distorted guitars and cool-guy Lou Reed-attitude. The third song, "Hill Climb," splits the difference; a cute pop tune along the lines of something by The Eels, with quirky instrumentation (is that a Mellotron listed in the liner notes?) that offers no apologies for its gentle nature. All band members and guest musicians seem experienced and capable, so there are, happily, no weak links. Singer Jon Schlesinger sings in a low register, almost spoken at times, which adds depth in the same way that Leonard Cohen's voice defines the mood of his own songs. The band experiments with different sounds and textures and shows no fear to step outside of the box, but they always end up in a pleasant pop environment.