助奏 is read as じょそう (josou) and means obbligato.
じょそう
josou
じょきょうじゅ
assistant professor
すけべえこんじょう
greed
すけべえ
lewdness
じょかんとく
assistant director (in taking professional movies)
じょこう
supporting attack
じょきょうゆ
assistant or associate professor
じょげんをあおぐ
to ask for advice
すけだち
helper
じょざい
auxiliary agent (dyeing)
じょねんざい
combustion improver
えんそう
musical performance
にじゅうそう
instrumental duet