PRAGUE (AP) — Rumors are that Wolfgang Amadeus Mozart and Antonio Salieri were archenemies. But a recently discovered piece shows they could work together.

The Czech Museum of Music presented on Tuesday a rare piece of music composed in three parts by Mozart, Salieri and an unknown composer, Cornetti, that was considered lost for more than 200 years.

The cantata "Per la Ricuperata Salute di Offelia" — "A Salute to the Recuperating Ophelia" — was composed in 1785 on a libretto by Vienna court poet Lorenzo Da Ponte. It was written to be sung to the Vienna-based English soprano Nancy Storace, to welcome her back to the stage after a brief loss of her singing voice.

It was also for Storace that Mozart and Da Ponte wrote the part of Susanna in "The Marriage of Figaro."

The original sheet with the libretto was acquired by the museum in 1949-50 in a collection of material.

German musicologist and composer Timo Jouko Herrmann first recognized the cantata's name when he was browsing the museum's online catalogues in November.

"We knew the title from advertising from 1785," Herrmann said. "I was thrilled when I read it. I thought 'could it be that the piece is in Prague and no one detected it?'"

Herrmann said Mozart and Salieri used to work together on other occasions at the time they were both based in Vienna, for example Salieri as composer and Mozart as pianist at the same year the cantata was written, but no other jointly written work is known.

It consists of three parts.

"The first part is by Salieri and is written in pastoral style," Herrmann said. "The second part is written by Mozart. It's more march-like rhythm, the beginning reminds me little bit of (Mozart's opera) "The Abduction from the Seraglio." And the third piece is by Cornetti. It's also written in more pastoral style, much closer to the piece Salieri wrote."

There were rumors, dismissed by authoritative sources, claiming that Salieri poisoned Mozart. Also Oscar winning "Amadeus" by Czech born director Milos Forman, based on a play by Peter Schaffer, imagined a deadly rivalry between the two and suggested that Salieri might have been behind Mozart's premature death at age 35.

Herrmann said the piece "shows a quite friendly outcome between the two composers."

Ulrich Leisinger from the Mozart Institute in Salzburg, Austria, said several Mozart's pieces have been discovered in the last decades but the latest one is significant because it is for the first time since 1906 that one of the compositions from the period he lived in Vienna was found.

"It's an original piece. There's no reason to doubt it is genuine."