This is actually a fix-up. The book is divided into 3 sections: with titles "Stardance," "Stardancers," "Starseed." The first part appeared in Analog March 1977 - and won both Hugo and Nebula awards for "best novella." The second 2 parts correspond to a 3-part serial in Analog (September through November 1978) which was titled "Stardance II."