a one-man band

an organization in which one person does all the work or has all the power

Usage notes: A one-man band is a musician who performs alone and plays several instruments at the same time.

It's basically a one-man band. He designs, prints and sells the T-shirts himself. Its critics say that the company has become a one-man band in recent years.

Common Names:

Name	Pronounced	Usage
Emil	E-mil (Swedish), E-meel (German, Polish), e-MEEL (English)	Swedish, Norwegian, Danish, German, Romanian, Bulgarian, Czech, Polish, Slovene, Serbian, Croatian,
'Isam	-	Arabic
Kennedy	KEN-ə-dee	English, Irish
Alekto	-	Greek Mythology
Leander	lee-AN-dər (English)	Greek Mythology (Latinized)
Husain	-	Arabic