The clarinetist plays an obligato, improvised part, also taking solo breaks. Finally, there is a bass. From a Jewish perspective, it should be noted that klezmorim, playing violins, cimbalom, and bass, were present in Hungary soon after 1700, and it appears that Gypsies only became established in this genre after 1750. There were a couple who played at Hungarian bars in Detroit with true Gypsy orchestras in the '50s, one a clarinetist named Gabor Zingenlaub. Romanian styles vary widely in different parts of the country, but let's look at lautari music in Bucharest, since it's the most accessible outside of Romania.
Instrumentation is more variable than in Hungary.
Beginning in the '20s or so, the large Hungarian cimbalom began to replace the small tsambal. After the war, the piano accordion became the most popular instrument, gradually driving out the violins. Clarinet and trumpet were other possible instruments. Romanian Gypsy music is mainly played at lautari weddings, which are the chief social events. There is usually a female singer, who might be accompanied by accordion, tsambal, and bass.