As for putting a face to Gubaidulina's extraordinarily visceral music, "She is very serious and a woman for whom religion is at the very core of her being."
Yet, he concurs, "She can write such very, very wild music."
One of the constants in this busy musician's life is his 1711 David Tecchler cello. You can hear it on disc playing Gubaidulina and, next week, it will be singing the romantic melodies of Schumann in the Town Hall.
"Tecchler was an Austrian who went to Italy so he could learn the craft of instrument-making," he explains. "I've had this cello since 1986 and, with all its overtones, it has an immense range of colour, creating a sound that carries well in the concert hall."
Schumann's 1850 Concerto is the last of the composer's major orchestral scores to maintain a place in the concert repertoire. Thedeen recorded it with the Malmo Symphony Orchestra in 1991 and still finds it a challenge.
"Schumann was an amazing composer for the piano. However, when writing for the cello, he expects us to move around various hand positions as if we were sailing over a keyboard."
He agrees, however, that this feature does give the Concerto an individuality and power, along with the volatility of Schumann's inspiration with those "schizophrenic outbursts of fast passages in the middle of slow, beautiful melodies".
Thedeen is looking forward to working again with English conductor Christopher Seaman and can look back on a long line of distinguished concert stage collaborators.
The main issue is one of communication, which is "the lung that enables music to breathe. Without communication, you might have great ideas but they won't work and, generally speaking, it's crucial that soloist and conductor are open to discussion."
When pressed to name a favourite, he opts for Vaclav Neumann, who was on the podium when Thedeen played the Dvorak Concerto with the Czech Philharmonic as a young man.
"A lot of conductors try to run the show a little bit too much," he laughs. "Neumann, though, was very humble and sweet and, most importantly, he listened."
A bonus for Auckland is a free Friday night masterclass that Thedeen will take in the University Music Theatre. He still remembers his own experiences as a young man taking in the wisdom of Paul Tortelier, Heinrich Schiff, William Pleeth and an ailing Jacqueline du Pre, which was "a great experience, but sad".
Now he appreciates the opportunity "to draw such energy from meeting young talented musicians who really want to do something that I can try and help them achieve".
Performance
What: Auckland Philharmonia Orchestra,
Where and when: Auckland Town Hall, Thursday at 7.30pm
What: Masterclass with Torleif Thedeen
Where and when: University of Auckland School of Music, 6 Symonds St, Friday at 7pm