Invisible Baby is easily the most out-there thing Marco Benevento has ever released, and it's also the most accessible.

Benevento and his piano, Mellotron, "circuit bent toys," and mountain of other keyboards in various states of disrepair blasted through Leslie speakers and a big humming amp are accompanied by Reed Mathis (Jacob Fred Jazz Odyssey and Tea Leaf Green) and drummers Andrew Barr (from the Slip) and Matt Chamberlain (a session ace who's played with everyone from David Bowie and Morrissey to Tori Amos and David Torn).

There are eight cuts here, all of them songs in the most proper sense of the word, completely drenched in sonic wackery, psychedelic spaciness, harmonic largesse, stretched rhythmic and dynamic play, and all manner of colors and textures.

Is it jazz? It depends on what your definition of that is these days.

It doesn't sound like anything else out there, and has more in common with people like Kenny Werner and Charlie Hunter, the Bad Plus, and E.S.T. than the standard jazz piano trio.

In fact, this resembles the latter not even a bit.

There are post-rockist elements at work here in the slowed tempos with somewhat studied pulses as well as volume excess in places, but that's not even the beginning of the story.

There are elements of classical wonkery at play: the Bartókian repetition in "If You Keep Asking Me," where the acoustic piano's middle and lower registers are enveloped in a kind of intervallic puzzle before they come sliding out toward the end with an entirely new melodic structure, is an example.

There are gonzo electronic effects that feel more like analog than digital (even if they are) and are glitchy, dirty, sloppy, and greasy, interlocking with an expansive knowledge and studied practice of the standards book (if only for the purpose of violation), as on "Ruby."

The playful attitude that begets "serious" music composition makes for a music that disregards genres while inundating itself in them.

Many genres work together at once, becoming a blur in Benevento's compositions.

Take the George Winston-like piano figure that opens "Record Book." Starting as a simple vamp, it begins -- with help from a rock-solid rhythm section that is subtly overlaid onto everything -- to become the voice of a singer.

Drama, memory, sorrow, travel, separation, distance, and the desire for a return to the known all come to play instrumentally as Benevento opens that melody up with rich harmonics and a sense of overlapping tonalities that are underscored by the sound of the other keyboards and toys being put through the Leslie.

This is a unique music that -- like the Bad Plus -- never disregards pop music (neither did Thelonious Monk) or makes fun of it, but finds its common elements not only useful but enjoyable and admirable in and of themselves.

Benevento uses everything from hip takes on '70s pop balladry (particularly the lonesome sound of Jackson Browne's piano playing and the decorative flair of Elton John's) to Radiohead's stretched-to-the-limit sense of time, the Pixies' humor, Röyksopp's and Air's electronic color palette, and They Might Be Giants' humorist experimentalism to make something uniquely his own in song form -- where improvisation, rhythm, sound, and space are the new thing.

If you need to know just how communicable it is, try playing the infectious "Atari" for a preschooler; you'll both be shaking it in the living room.

If this is jazz, give us more; if it's the new avant-garde, it needs to be played on the radio; if it's the new post-pop/rock & roll sound, it's got more rhythm than all that stuff put together.

Whatever it is, it's delightful, fun, complex, and hummable most of the time -- and it's not for those who like their genres clearly defined.