Grat - Edge is a personal homage by cellist Friedrich Gauwerky to his lifelong friend Wolfgang Rihm, recorded for the composer's 70th birthday. Five works for and with cello, from a string trio of 1969 to a cello and piano piece of 1993, cover a broad spectrum of Rihm's writing and include two first recordings.

Rihm, born on 13 March 1952, was one of the most performed and prolific composers of his time; he died in Ettlingen on 27 July 2024. He and Gauwerky, one year older, met in 1968 when they shared a room for a week at a competition for young musicians in Erlangen. Gauwerky has played Rihm's music throughout his career, and has also been principal cellist of Ensemble Modern, a member of the Elision Ensemble in Australia, and a teacher at the Darmstadt Summer Courses. He is joined by violinist Alexandra Greffin-Klein, violist Axel Porath and pianist Florian Uhlig. The recording was made on 19-21 November 2021 in the Kammermusiksaal of Deutschlandfunk in Cologne, produced by Frank Kämpfer, as a co-production with Deutschlandradio.

The title work, Grat (Edge) for solo cello (1972), is the wild and unbridled virtuoso piece that Gauwerky has carried through his whole career. The early Streichtrio Nr. 2 (1969), never published, contains allusions to Alban Berg's lyrical twelve-tone writing. von weit, in its Antlitz version for cello and piano (1993), and duomonolog for violin and cello (1986/89) show the later Rihm, while the Streichtrio op. 9 (1971) returns to his beginnings. duomonolog and the op. 9 trio are heard here for the first time on disc.

Gauwerky has said of his friend that "as a composer he almost always comes up with something unexpected, unpredictable, and new", and that he tried to show this breadth through the choice of works. Since Rihm's death the album also stands as a portrait made by someone who knew the music from its first years. The booklet contains texts in German and English, with liner notes by Rainer Nonnenmann.

CD, Wergo WER 7402 2, released in 2022, total time 48'26".