ROME (AP) — Instruments made from smugglers’ boats that brought migrants to Italy’s shores told their tale of desperation and redemption in a special performance at a prison in Milan on Saturday, in front of the inmates who made them.

World-renowned Italian conductor Riccardo Muti led the Cherubini Youth Orchestra, whose members played on violins, violas and cellos distinguishable by the faded blue, green and yellow paint of salvaged wood.

“These instruments are made from the tragic wood of these boats that were trying to bring people to safety and democracy,” Muti explained to an audience of inmates and guests at the Opera prison, the largest in Italy.

The makers who created these unique instruments are taking part in a project — dubbed Metamorphosis — that focuses on transforming what otherwise might be discarded into something of value to society: rotten wood into fine instruments, inmates into craftsmen, all under the principle of rehabilitation.

“Hearing these people, who are here serving their sentences, but who seem so serene and so clearly and openly eager to find a sense of harmony in their lives through music … has been an enrichment of my experience as a musician and as a man,” Muti said after the performance.

The Opera prison on Milan’s southern edge has over 1,400 inmates, including 101 mafiosi held under a strict regime of near-total isolation.

The boats arrived at Opera after being seized, some still containing remnants of the migrants’ belongings, and with them a reminder of the tens of thousands of migrants that the U.N. says have died or gone missing on the perilous central Mediterranean crossing between Africa and Europe since 2014.

On Saturday the orchestra performed pieces from Italian composers Antonio Vivaldi and Giuseppe Verdi and a chorus with singers from another Milan prison, San Vittore, joined for a rendition of “Va’ Pensiero,” also known as “The Chorus of the Hebrew Slaves,” from Verdi’s masterpiece “Nabucco.”