When singers take to the stage, Peter Lockwood's work is done.
In fact, you could argue his job is done even earlier than that, when they arrive at the first rehearsal.
The New Zealand-born, Netherlands based vocal coach has been the power behind some of Europe's best voices for the best part of four decades, the past three of them based at the Dutch National Opera in Amsterdam.
Lockwood recently retired from that role, but remains a freelance vocal coach and repetiteur, which meant he was able to return to New Zealand recently for a three-month stint filling in at Te Pae Kōkako - The Aotearoa New Zealand Opera Studio (TANZOS) at Waikato University, so its usual director Madeleine Pierard could get away and do some actual opera singing.
Before Lockwood headed back to Europe, he sat down with RNZ Concert host Bryan Crump to talk about his work, and his love of opera.
Although he's sung in choirs, Lockwood came to music through the piano, but he enjoys making music with singers above all else.
So what does a repetiteur do? Pretty much everything, Lockwood says: being the singer's orchestra when there is none, offering advice on phrasing, technique and language.
Lockwood has to know the opera his singers are preparing for as well as a conductor, and he has the best part of two hundred under his belt.
Does he wish he could have been a singer?
Sometimes, but to be part of the opera world (Lockwood says nothing beats the human voice for emotional impact) is enough.
Crump asks about his favourite opera moment, and Lockwood has a frog in his throat as he describes the duet, "Sono andati" ("They have gone") towards the end of Puccini's La bohème.
Here's a snippet of the great Mirella Freni and Luciano Pavarotti singing it - might leave you feeling a bit gooey, too.