Operas from the English National Opera (ENO) are to get surtitles, despite all performances being sung in English.
The ENO performed at the Glastonbury Festival last year
Surtitles are used primarily to help audiences follow the lyrics in foreign language productions.
But the ENO said they were responding to audience demand to see the singer's words written above the stage.
ENO artistic director Sean Doran said the large size of the London Coliseum - the ENO's home - meant surtitles were a "vital" addition.
He said the audience's enjoyment of the opera was currently being "compromised", as some lyrics can be inaudible.
"The majority of the audience are really crying out for it," said Mr Doran, who is also the ENO's chief executive.
"There are definitely opposing views, but we will be catering for people who don't want surtitles with one or two performances which don't use them during each production.
"One problem is the size of the Coliseum. With 2,400 seats, its the biggest lyrical theatre in the country.
"I've sat in the auditorium during performances and things are being missed, you hear the audience talking about it afterwards."
Mr Doran said research showed 61% of its audience was more likely to return to the Coliseum if surtitles were used.
They will be introduced from March 2006, beginning with Vaughan Williams' Sir John In Love.
Mr Doran added: "When Lilian Baylis founded this company in 1931, her mission was to make opera as accessible as possible.
"Surtitles as a tool are vital if ENO is to continue this mission and continue to attract audiences to the London Coliseum.
"I have no doubt that were Lilian alive today she wouldn't hesitate to introduce surtitles for the audience's benefit."