Though musicologists who specialize in Gustav Mahler have long taken the memoirs of his wife, Alma, with a grain of salt, most of them have accepted her portrait of him as a fairly chaste ascetic who had few romances before he met her. Now, two scholars say a recently discovered letter from a Mahler confidante — and sometime lover — Natalie Bauer-Lechner, instead shows that he had numerous affairs and infatuations.

“The letter is a fairly complete account of love affairs with quite a number of people, starting with his involvement with a woman named Josephine Poisl, the daughter of the postman in Iglau, his hometown,” said Stephen E. Hefling, one of the scholars, who hopes to publish the document.

The 59-page letter, handwritten in German and called “Brief über Mahlers Lieben” (“Letter About Mahler’s Loves”), was written to Hans Riehl, one of Bauer-Lechner’s heirs, and should bring a new dimension to a composer whose titanic symphonies and bittersweet songs have become an increasingly central part of the classical repertory over the last 50 years, but who is often seen as an intensely brooding, introspective figure. Now he may be seen as less severe, and at times fairly randy. (Bauer-Lechner does not discuss whether Mahler had any affairs after his marriage. That was Alma’s department: Mahler’s despair on discovering her romance with the architect Walter Gropius caused him to seek advice from Sigmund Freud.)

Bauer-Lechner, a violist, is hardly unknown in Mahler circles. The journal she kept during their long friendship — they met as students — was published in 1923, two years after her death (and 12 years after Mahler’s, at 50) and is regarded as an important way around what some Mahler specialists call “the Alma Problem,” meaning the nearly exclusive control of information about Mahler that his widow wielded for so many years.