This collection contains musical birthday greetings to composers and instrumentalists who are close friends of Heinz Holliger. The very different pieces were created over a period of 15 years for the duo Ursula and Heinz Holliger. Among the recipients of these birthday compositions were Elliott Carter, Pierre Boulez, Robert Suter, György Kurtág, Emile Cassagnaud, and Maria Teresa Cerocchi, among others.