An oboist who played with Welsh National Opera (WNO) for 34 years has lost his claim of wrongful dismissal.
Murray "Sandy" Johnston, 61, claimed he had been bullied and harassed by former musical director Carlo Rizzi.
But an employment tribunal in Cardiff heard Mr Johnston was sacked because his playing risked the orchestra's reputation.
The tribunal ruled the musician was fairly dismissed.
Mr Johnston claimed wrongful dismissal alleging Mr Rizzi bullied and "persistently abused" him in a 16-year vendetta.
He told the tribunal that any problems with the orchestra's wind section were not his fault alone.
But Jason French-Williams, defending the WNO, told tribunal judges: "We have heard from the respondent in evidence that it considered itself to be a world-level company.
"It follows, therefore, that it is vital that the performers who play for that company are capable of playing at the very high level."
He said failure to remove somebody whose playing had fallen below the required level put the company's reputation at risk.
Tribunal judges adjourned proceedings after the hearing ended on Thursday but their judgement was revealed on Friday.
Responding to the ruling, WNO managing director Peter Bellingham said: "The decision to dismiss Mr Johnston was taken after genuine concerns about his playing were raised by the then music director, Carlo Rizzi.
"There followed a process of monitoring that spanned nearly four years during which time it was made clear to him what the shortcomings were and how he should address them.
"When it was clear that the situation was not going to be addressed to our satisfaction we had no option but to dismiss Mr Johnston in order to protect the reputation and high artistic standards of the company.
Mr Bellingham added: "It was a decision taking entirely on artistic grounds, one that is vindicated not only by the tribunal's decision today but also evidenced by the very high quality of playing in the orchestra at this current time.
"On a personal level it is always very unfortunate when someone with such long service loses their job but in this case, having exhausted every possible avenue to bring about an improvement, we took this step to protect the artistic integrity of the company."