But according to Ms. Rowe’s lawsuit, which seeks $200,000 in unpaid wages, pay disparities can be significant. Ms. Rowe, 44, is paid about $70,000 less each year than John Ferrillo, 62, the principal oboist, based on data in the lawsuit and tax records. That is despite the fact that they play next to each other and are both “leaders of the orchestra in similarly demanding artistic roles,” according to the lawsuit, which was first reported by The Boston Herald.

Ms. Rowe, who previously held positions in Baltimore, Washington and Indiana, joined the Boston Symphony in 2004. She has been a featured soloist with the orchestra 27 times, more than any other principal musician, according to the lawsuit. Critics for The New York Times have called her playing “ravishing” and “splendid.”

She has also been a “face of the orchestra,” the lawsuit says, frequently featured in marketing campaigns, donor-relations events and tours, like last year’s visit to Japan, when she and the principal harpist Jessica Zhou — the only other female principal player — were the only musicians from the orchestra featured as soloists.

Setting pay for orchestral musicians is complex. Collective bargaining agreements guarantee a minimum base salary, but principal players and others generally negotiate significant “overscales” based on solo fees, costs of instrument ownership, promotional duties and other variables.

Drew McManus, an arts consultant who has advised musicians on contract negotiations, said that many orchestras fail to be rigorous in quantifying a musician’s value, allowing room for bias.