There's only one Vatican organist, American James Edward Goettsche, who has held the post since 1989.
But another master of the pipes is claiming papal endorsement ahead of an international tour.
"Any other person claiming the same title and the same merits is an
imposter," wrote Cardinal Francesco Marchisano, archpriest of Saint Peter's Basilica.
The warning is apparently aimed at a young Italian organist, Massimiliano Muzzi, who has billed himself "the organist of Pope Benedict XVI" ahead of a tour of the United States, Germany and New Zealand.
The Vatican alleges that Muzzi is falsely using the title to further his career and Goettsche has not ruled out taking legal action if the cardinal's warning is not heeded.
So far not a squeak from Muzzi himself.