For fans of Craig Taborn's electronics-oriented recorded work or for those who prefer his early trio records or his sideman appearances with James Carter, a solo acoustic piano recording on ECM might come as a bit of a surprise, but it shouldn't. Taborn's been playing solo shows for over a decade -- most of them improvised -- and it's that part of his musical character that displays itself on Avenging Angel. Taborn has always been interested in the language of the instrument itself, the possibilities of its tonalities, spaces, textures, echoes, etc. The 13 pieces here, recorded on a gorgeous Steinway piano in Lugano, Switzerland, elaborate magnificently on all of those notions and more, without sounding overly ponderous or studied. These pieces range widely; each has its own motivation, form, frame, and intention; each arrives at a different destination. "The Broad Day King" begins with quiet, even delicate high-register notes that resemble wind chimes in a gentle breeze, and is colored as it evolves by descending chord patterns with deliberate spatial elements to delineate them from that intro while extending its memory. The title track commences with mildly dissonant two- and three-note chords in the lower-middle register, playing a pulsing if syncopated rhythm as the right hand adds accents and contrapuntal voicings to create the appearance of a dual melody, though only one eventually emerges. "Gift Horse/Over the Water" asserts a series of scalar studies before dynamically raising its head and using jagged chords to move from one half of the tune to the other. "Spirit Hard Knock" commences by using sharply angled single-note improvisation before assembling a dreamy series of lyric phrases. Taborn's use of the instrument itself is quite physical: at times he plays ppp (where restrained force is employed to push on the key just enough to get a sound), while other notes or short segments employ Sforzando. The elliptical nature of "Forgetful" is the set's most beautiful and elliptical number, emerging from the ghostly trace of a lyric melody into a fully realized spherical one; despite its dynamic changes -- which are gradual -- it never surrenders its deliberate spaciousness where sound itself -- the moments after single keys or chords are struck -- lingers and holds momentarily, before others replace them. Avenging Angel is not an intellectual exercise, it is a major contribution to the actual language of the piano as an improvisational instrument: its 13 pieces feel like a suite: seamless, economical, original, and visionary.