“Boo” – the name is as unusual as the sound is special. The avant-garde composer Harry Partch invented instruments for micro-sounds and completely new musical experiences. The musician and instrument maker Thomas Meixner dedicated two years of his life, marked by family and health losses, to rebuilding 75 of these sound-generators for a concert tour. The film portrays a monomaniac who fiercely avoids social life but with great sensitivity makes material sing.