I Fagiolini may be called “The Little Beans” in Italian, but they make a big, beautiful choral sound.

I’m dying to ask Robert Hollingworth what it’s like to conduct Spem in Alium.Golden strands of vocal polyphony in no less than 40 parts weave their way through Thomas Tallis’s sublime masterpiece of the English Renaissance, which will be performed by Hollingworth and his British group I Fagiolini at the Perth Festival this week. Does he ever feel overwhelmed in the face of that rich choral tapestry? Conducting in the round as luminous voices wash over him, does he ever want to throw down his baton, close his eyes and simply soak up the sound?

“Actually, it’s like driving a monster truck,” he says gleefully. “The forces are so enormous.” Hearing his refined Oxford accent and clear singer’s diction over the phone, it’s hard to imagine him driving anything gutsier than a Volvo, but then, it’s easy to underestimate the power of this magnificent Tudor motet, in terms of sheer size and emotional impact.

“Enormous” is relatively new to I Fagiolini, a band of singers long associated with Monteverdi madrigals and intimate Renaissance repertoire. So what made them decide to supersize?