Book of Ways is a double album of nineteen improvisations that Keith Jarrett played on the clavichord. It is a Baroque keyboard so quiet that, in his words, it "cannot be heard more than a few feet away". Made in a single four-hour session in July 1986 and first released in 1987, it has no piano and no prepared material. ECM's own note hears unmistakable echoes of lute music and of the Japanese koto in it.

The session took place on 14 July 1986 at Tonstudio Bauer in Ludwigsburg, on a day off between concerts with his trio; the night before, Gary Peacock and Jack DeJohnette had joined him in Munich for Still Live. Manfred Eicher produced and Martin Wieland engineered. Looking back in 2002, Jarrett recalled three clavichords in the studio, two angled together so that he could play both at once, the third off to the side. The instruments were miked very closely so the full dynamic range could be used, nothing was organised beforehand, and the whole recording took four hours.

The improvisations keep the order in which they were played. Jarrett moves between one instrument and two at a time, and the doubled clavichords give some pieces a thick, ringing resonance. Book of Ways 1 opens like a lute song, balanced and unhurried. Book of Ways 10 is percussive and insistent, struck rather than sung. Book of Ways 18, one of the longest pieces, is slow and mournful, a "funereal ode" in the words of Tyran Grillo of ECM Reviews.

On its release Spin heard music that "comes right at you, insists that you listen to it", played with Jarrett's "accustomed inwardness" yet a paradoxically greater objectivity and force. Jarrett himself, writing in 2002, considered the recording "unique in several ways". Grillo heard Book of Ways 9 as a nod to the Baroque keyboard masters, made with sounds that are entirely its own.

This is the 2023 double CD reissue on ECM Records, ECM 1344/45, in new packaging with high-grade paper sleeves and gold embossed lettering. The album was first released in September 1987.