In his Hamburg Concerto dedicated to Marie Luise Neunecker, György Ligeti draws on the inherent qualities of the natural horn, looking for an alternative to equal temperament. In order to refresh his harmony, he combines a solo horn (or alternatively an F–B flat valve instrument and a natural one in F) with four variously tuned natural horns in the orchestra. The natural harmonics form unusual, fluid chord combinations. Together with the non-European rhythmic patterns used by the composer, these create a fascinating contrast with the quasi-choral sections in which the tonal spectra are specially highlighted.