When you see on the CD package that this is an Extended Play release running just under 30 minutes, you might expect something short and sweet or compact and dense, but what you get is all of the above and more.

The playfulness of Mary Halvorson's guitar wizardry and Hubert Bergmann's piano percolations give this a whimsical touch at times, but the seemingly inexhaustible inventiveness and tireless technical tight-wire dancing are enough to make you gasp, and when the end comes, you wonder "Is it really over?"

Not that this is a huge wall of sound that never lets up. Although it is that at times, there are nice contrasts of subtle moments amid the racing ideas, and while there is never a solo moment, per se, the two musicians are wise enough to play off each other in ways that highlight the other's lines and help the improvisation and interplay evolve in unpredictable and engaging ways.

If this were a painting it would resemble something like a Kandinsky, with its wild, bold streaks, swirling forms, bold blocks of color, play of foreground and background in a relentless inventive frenzy.

A musical polyglot as far as the avant-garde goes, Halvorson has honed her chops to fit any situation, it seems, since she seems right at home in musical settings like Anthony Braxton's groups, as well as work in duos, trios, a quintet and an avant-rock band.

While he has collaborated in larger projects, Bergmann has mostly worked in the solo or duo variety, so this is a familiar setting for him and it shows when he stretches out in ways that redefine stretching out...almost as if he's climbing the mountains of his imagination in totally unfettered fashion, with Halvorson following right along until they reach the summit, taking the listener to breath-taking heights.