"No matter how many times I conduct this symphony, I always feel the same excitement," Gourlay says. "Astonishingly, it never grows tired one me."
The strength of this 1953 titan lies in its strong sense of place, Gourlay decides, and he sees an almost magical scenario in Shostakovich's writing of the work.
"Although it was composed pretty quickly, the ideas behind the symphony had been simmering over a long period of time. Suddenly the trigger to set it off came with the death of Stalin, unlocking the remarkable journey that this symphony is."
Compared to a recent concert where he had to learn 90 minutes of hardcore avant-garde music that he will probably never conduct again, Shostakovich's symphony seems like an old friend.
"I have it very securely inside me," he says. "And I feel that I'm able to take it to the next level, incorporating all the previous experiences that I've had with it."
Gourlay's own career has taken him most recently to Spain, where he's music director of the Orcquestra Sinfonica de Castille y Leon, based in the city of Valladolid and serving an area about the size of Austria.
"This is heartland Spain," he says. "We're lucky that the government supports us to do high-level stuff which means that this season we have guest soloist such as violinist Vadim Repin and pianist Nikolai Lugansky."
Gourlay talks of having to smarten up his Spanish language skills to cope with all-important communication but is cautious when it comes to conducting Spanish music.
"I've seen too many foreign conductors take on the very English Elgar when it's not in their blood," he explains. "I feel that you have to grow up with some music to get the authentic touch."
Not that this has stopped him encouraging young Spanish composers, workshopping submitted scores and performing the best in concert.
"The orchestral players vote on all this, which means that they are connected with the whole business of commissioning, discovering local music that otherwise would remain under the surface."
What: Auckland Philharmonia Orchestra - Defiance.
Where & when: Auckland Town Hall, Thursday