Different tunings in same piece?

[kristopaivinen]

I thought about the idea that different instruments are usually tempered according to the same system when playing a single piece, and wondered what would happen if one composed a piece where different instruments are tempered differently, for example a piece for piano and violin where the piano would be tuned to to the 12-tone equal temperament, and the violin would be tuned to just intonation. What possibilities are there for doing such things, and who has ever done it?

[Symphonien]

Ligeti did this quite notably in his Violin Concerto - the solo violin and viola from the orchestra are tuned differently to the rest of the players. The solo violin tunes the E string in tune with the double bass's seventh natural harmonic on the G string (sounding 45 cents lower than a normal F) and then tunes the other strings to the sharp E string in perfect fifths. The viola does the same on the D string with the fifth natural harmonic on the double bass's A string (14 cents lower than C#). He also writes some microtones for the woodwinds and when they double on ocarinas in a couple of passages, instructs them not to correct their sharp tuning when playing forte. Horns and trombones also play natural harmonics on several occasions, with the intonation also not corrected.

The natural violin harmonics have their greatest effect in creating the glassy, shimmering quality of the first movement. Ligeti writes in the score that the "not always correctly sounding-harmonics" create the impression of fragility and danger.

He experimented further with different tunings in his Hamburg Concerto, for solo horn and chamber orchestra, with four obligato natural horns. He describes it as follows in the notes for The Ligeti Project IV:

In this piece I experimented with very unusual non-harmonic sound spectra. In the small orchestra there are four natural horns, each of which can produce the 2nd to the 16th overtone. By providing each horn or group of horns with different fundamentals I was able to construct novel sound spectra from the resulting overtones. These harmonies, which had never been used before, sound "weird" in relation to harmonic spectra. I developed both "weird" consonant and dissonant harmonies, with complex beats. Horns blend very well together, and to enrich the sound further, the two clarinettists play basset horns. Even though it is replete with spectra of strange beats, the resulting overall sound is soft and mellow.

These are two very interesting pieces that I recommend you to check out if you're interested in this sort of thing. I especially enjoy the violin concerto, which is probably my favourite work of Ligeti.

[lukeottevanger]

Only just saw this.

The Ligeti example is a good one, because the horn and trombone parts, playing natural harmonics, are sometimes in conflict with the rest of the equal-tempered orchestra. As Symphonien says, Ligeti does this in other scores too, notably the horn trio - it's always been a concern of his (we see it in the second string quartet, which is a much earlier work). The ocarinas and swanee whistles in the Violin Concerto also use a different tuning to the rest of the orchestra - or rather, they are simply, and deliberately, out-of-tune. However, the two solo strings which tune to the double bass are not operating to a different tuning system, as per the OP's request - they are simply tuned to a different note - Ligeti also does this in e.g. Ramifications (two string orchestras a quarter-tone apart) and other composers have done similar things.

However, Ligeti was preceded in his partiality for natural harmonics in an ET context - slightly so by Britten, whose Serenade asks for the odd natural harmonic in the solo horn part (but only ever unaccompanied); much more so by Vaughan Williams, who in a quietly outrageous mood asks for naturally tuned brass fanfares in the Pastoral Symphony.

Two more works which use different and co-existent tuning systems spring to mind:

Lou Harrison's Piano Concerto, in which the piano's white keys are tuned to just intonation and the black keys to ....something else  I'm sure there are other pieces of Harrison's which work similarly.

John Adams' The Dharma at Big Sur, which was orignally intended to be in just intonation; when he realised this wasn't workable, Adams rewrote it in ET, but kept the electronic sounds in JT.