Stas performs on the 'B' system bayan by Petosa. This full-size, 5 octave concert accordion has 120 buttons arranged in six rows on the left hand, and 106 buttons arranged in five rows along the keyboard on the right  hand. Increasing the bayan's ability to produce an incredible range  and spectrum of sounds are 15 registers (stops) on the right, five in the bass, and seven chin registers.

The bayan was invented in the early 20th century, and the first solo bayan concert occurred in 1935 in St. Petersburg. It is one of the most  beloved folk instruments in Russia. At first all original music for  the bayan was composed by bayanists for their own use, but when the  modern composers began to create serious concert works for the instrument it came to be respected as a classical instrument. It's versatility  lends itself to all types of music.