From Longman Dictionary of Contemporary Englishone-man bandˌone-man ˈband noun [countable] 1 informalONLY an organization or activity in which one person does everything The company is really a one-man band.2 APMa street musician who plays several instruments at the same time
Examples from the Corpus
one-man band• But as a one-man band, his overheads were similarly negligible.• Can a journalist ferret out the facts while operating as a one-man band?• It's a small local radio station, really just a one-man band.• Lunchtime on a day in June, cadenza in the rising wind: is there anything wrong with a one-man band?• An impressive variety of practices is featured in the exhibition, from the one-man band to the big, quoted companies. 