Before the gig economy consumed a third of the workforce, it was mostly musicians who worried about gigs. There are debates about the origins of the word-some believe it derives from an eighteenth-century term for horse-drawn carriages that may have doubled as stages for performers, while others contend that it was adapted from a Baroque dance called the gigue. But the "gig," as shorthand for a casual, oneoff paid performance, entered the popular lexicon during the Jazz Age of the nineteen-twenties and thirties. There was a mystique to the gigging musician wandering the big city in search of work, because this work was creative, improvisational, at times transcendent.

Young people who came of age before the twenty-first century, Franz Nicolay argues in a new book called "Band People: Life and Work in Popular Music," could be forgiven for assuming that working one's way up from gigs to a steady job in music was a plausible career path. You might not make it as a chart-topping star, but there were still opportunities for "band people"the "hired guns" or "side-of-the-stagers" who offered structure and support.

Music was everywhere, and there had to be people to play it. Nicolay's book details the lives of working musicians, especially those far from the spotlight: background vocalists hired for uncredited recording sessions, rhythm guitarists playing on freelance contracts. Not that the spotlight in question shines all that brightly to begin with; most of the dozens of artists Nicolay spoke to work in commercially tenuous realms, such as indie rock or punk, in which a band like Sonic Youth represents the imagination's zenith.