You have to have a vivid picture of the music and the composer's intentions in your head to make a difference to the musicians and audience, conductor Dane Lam says.
Acclaimed as one of the most talented young conductors Australia has produced, he is conducting the Southern Sinfonia's concert on Saturday.
He tries to figure out what might have been going on in the composer's head when he or she was writing the piece, what was happening in their life and cultural milieu, what was happening in the music itself, and what message it might convey, then try to bring that out in the performance, even if he can't put it into words.
"It's not dogmatic, it's personal and your interpretation is always going to be coloured by your beliefs on things, and that's what makes music so interesting.
"It's never the same."
The main item in Saturday's concert is William Walton's Belshazzar's Feast, a cantata sung by the City of Dunedin Choir with British-based New Zealand bass-baritone Paul Whelan as soloist.
"It is unashamedly a vulgar piece in terms of just how big and noisy it really is, but it's really stirring, evocative music.
"I'm still trying to decide what the message is."
The cantata is so dramatic, it could almost be staged, he said.
It tells the story of Belshazzar, the king of Babylon who enslaved the Israelites. While he drinks from the sacred vessels looted from the Jewish temple while worshipping his own gods, a mysterious hand appears and writes on the wall. That night Belshazzar is slain by God and the Israelites rejoice.
"But the interesting thing is, some of what seems to me his most convincing and successful music comes when he's depicting the pagan rituals and drinking from the sacred vessels while worshipping the false gods.
"Then when it comes to the rejoicing, it's a little bit hollow. I don't know whether he's commenting on the hypocrisy of religion in general, or the danger of feeling so wonderful and pious and religious when there's actually some viciousness in that too, because the Israelites are talking about striking the heads of the first-born children of the Babylonians against stones and things like that," he said.
"I mean two wrongs don't make a right. I don't know if it's reflected in the music - I think it might be. It's all very ambiguous."
Lam suspects Walton may be tongue in cheek about it all.
"He knows he's being overblown. The last pages and pages of the score are fortissimo with the whole choir and whole orchestra praising God, and it seems a little bit hollow. It's just so loud - it's like the end of Shostakovich's Sixth Symphony where there's this big, triumphant music, but he's really poking fun at the Stalin regime because it's just so overblown and so triumphant - it's a parody in a way."
Walton wrote the work between the two world wars (it was first performed in 1931) and it sounds as if he was disillusioned with something.
It is loud with jazz harmonies, a lot of shouting, and originally was performed with an off-stage brass band, Lam said.
"Sir Thomas Beecham was conducting it and he said to Walton, you have these musicians at your disposal and this work is so terrible it's never going to be performed again so you might as well write it for off-stage brass and just enjoy it, so he did."
Contrary to Sir Thomas Beecham's prediction, Belshazzar's Feast has become one of Walton's most celebrated works, although the off-stage brass band parts are now usually played by the brass section of the orchestra.
It comes from the English choral tradition and the words from the King James Bible and Osbert Sitwell, but is hard-edged like much German music, and has jazz harmonies associated with American music, he said.
The other two works in the programme are quite different, although they share a similar theme of religiosity and faith, he said.
Ralph Vaughan Williams' Fantasia on a theme by Thomas Tallis (1910) is solemn, sincere, stern and peaceful.
"It's based on plainchant by Tallis that he discovered so has this medieval kind of mystic feel to it."
It is for a string orchestra divided into three, a quartet, a main orchestra and a second orchestra placed away from the main orchestra to create a kind of stereophonic effect, he said.
"They all have distinct personalities and it's interesting to hear an impassioned outburst from the main orchestra, and an ascetic, almost meditative reply from the second orchestra, then the quartet comments on things as well. It's such English music, it's so beautiful."
On the other hand, Aaron Copland's Appalachian Spring is American and was originally written in 1944 for a ballet by Martha Graham, an influential modern dancer and choreographer.
"I feel connected to that tradition a little bit because she had a lot to do with Julliard where I did my studies in the US. It's quite a simple story and again has that religious undertone."
The story is of a slightly naive young Shaker couple getting married and the trials and tribulations they undergo in married life. Copland's music is quintessentially American with slightly hazy sounds from added notes and Shaker hymn tunes like Simple Gifts, better known in recent times as Lord of the Dance.
"The hymn tunes of America make up such a part of its heritage, and it all comes together for this piece. It has beautiful still, soft sections and rollicking dance-like sections and playful sections. There is everything in that piece. It has to be one of the most American of American pieces."
At present a junior fellow in conducting at the Royal Northern College of Music in Manchester, UK, Lam (26) grew up in Brisbane learning music from childhood. One day in high school he saw some senior pupils conducting and thought he could do that and when the teacher left the room he started conducting. About the same time he realised that music could be a career, and was lucky enough to get on a course for school-age conductors with Symphony Australia.
"Conducting felt like a good fit when I first started. I found it really interesting, not just the performance side, but also the historical side, the philosophical side, the spiritual side - it's very stimulating," he said.
• HEAR IT
On Saturday, July 16, at 8pm in the Dunedin Town Hall, the Southern Sinfonia, conducted by Dane Lam, will perform William Walton's Belshazzar's Feast with bass-baritone Paul Whelan and the City of Dunedin Choir, Vaughan Williams' Fantasia on a Theme by Thomas Tallis, and Aaron Copland's Appalachian Spring.
