When Barcelona’s opera house reopened this week, its first concert in three months was played in front of a full house… of plants.

The Spanish venue opened on Monday evening with a performance by the UceLi Quartet, who played the opera house’s first concert since mid-March.

It sounds like a solitary undertaking, but don’t worry. Even though a human audience was out of the question, the organisers made sure the musicians didn’t leaf empty handed.

Rather than letting a garden variety concert happen sans audience, the Gran Teatre del Liceu decided to go out on a limb, teaming up up with conceptual artist Eugenio Ampudia to fill every one of the 2292 seats for Concierto para el biocene with a potted plant.

As opera fans, they may have been a little green, but we’re betting that the musicians loved having an audience there, rooting for them. According to NPR, the string quartet serenaded its leafy audience with a performance of Puccini’s Crisantemi, which was later made available human listeners via a livestream.

The shrubs aren’t done branching out either, they’ll be turning over a new leaf when the opera house donates them to health care professionals working at the Hospital Clínic of Barcelona.

“After a strange, painful period, the creator, the Liceu’s artistic director and the curator Blanca de la Torre offer us a different perspective for our return to activity, a perspective that brings us closer to something as essential as our relationship with nature,” reads a statement on the opera house’s website.

“The Liceu, one of the largest and most important opera halls in the world, thus welcomes and leads a highly symbolic act that defends the value of art, music and nature as a letter of introduction to our return to activity.”

Like many European nations, Spain is taking tentative steps towards reopening, opting for a phased approach. The country ended its national state of emergency on Sunday, lifting the COVID-19 lockdown restrictions that had been in place for three months.

Human viewers can watch full livestream of the Barcelona Opera House’s premiere performance on YouTube.