The troubadours, those early balladeers whose art sprang forth from the south of France in the 11th century and formed the basis of the solo song still enjoyed today, were given their due in an excellent concert by the Folger Consort Saturday night in the Great Hall of the Folger Library. The concert, titled "The Flowering of Song," presented works by Marcabru, Raimbaut de Vaqueras and Jehannot de L'escurel.

The consort was joined in this performance by guests Tina Chancey on bowed strings and vocal soloists Peter Becker and Louri Monahan, both of whom displayed voices of unfailing sumptuousness that were nevertheless totally within the character of the music. Becker's performance of Marcabru's "The Other Day Beside a Hedge," and Monahan's of "I Am Obliged to Sing" by La Comtessa de Dia were hauntingly beautiful. Here are two musicians who seem thoroughly steeped in the idiom.

The instrumental selections were no less engaging. Especially tantalizing was the set of pieces by L'escurel that were imbued with a spicy Middle Eastern flavor, the troubadours having been influenced by the Moslem culture of Spain and North Africa. "The Song of the Flood," an anonymous piece delivered with elegance by the group, had an oddly Appalachian flavor, due probably to the prominence of Scott Reiss' dulcimer.

The concert will be repeated tonight in the Elizabethan Theater at the Folger.