Horn and Orchestra requires the performer to simultaneously produce two notes by humming while playing—a technique known as "multiphonics". His bassoon concerto and the Andante e Rondo ungarese (a reworking of a piece originally for viola and orchestra) are also popular with bassoonists. Weber's contribution to vocal and choral music is also significant. His body of Catholic religious music was highly popular in 19th-century Germany, and he composed one of the earliest song cycles, Die Temperamente beim Verluste der Geliebten ([Four] Temperaments on the Loss of a Lover). Weber was also notable as one of the first conductors to conduct without a piano or violin. Weber's orchestration has also been highly praised and emulated by later generations of composers – Berlioz referred to him several times in his Treatise on Instrumentation while Debussy remarked that the sound of the Weber orchestra was obtained through the scrutiny of the soul of each instrument. His operas influenced the work of later opera composers, especially in Germany, such as Marschner, Meyerbeer and Wagner, as well as several nationalist 19th-century composers such as Glinka. Homage has been paid to Weber by many 20th-century composers, such as Debussy and Stravinsky. Mahler completed Weber's unfinished comic opera Die drei Pintos and made revisions of Euryanthe and Oberon while Hindemith composed the popular Symphonic Metamorphosis of Themes by Carl Maria von Weber, based on Weber's lesser-known keyboard works and the incidental music to Turandot. Weber also wrote music journalism and was interested in folksong, and learned lithography to engrave his own works. A virtuoso pianist himself, Weber composed four sonatas, two concertos and the Konzertstück in F minor (concert piece), which inspired composers such as Chopin, Liszt and Mendelssohn. The provided a new model for the one-movement concerto in several contrasting sections (such as Liszt's, who often played the work), and was acknowledged by Stravinsky as the model for his Capriccio for Piano and Orchestra. Weber's shorter piano pieces, such as the Invitation to the Dance, were later orchestrated by Berlioz, while his Polacca Brillante was later set for piano and orchestra by Liszt. However, Weber's piano music all but disappeared from the repertoire. There are several recordings of the major works for the solo piano, including complete recordings of the piano sonatas and the shorter piano pieces, and there are recordings of the individual sonatas by Claudio Arrau (1st sonata), Alfred Cortot and Emil Gilels (2nd