If versatility is a musical virtue, then mezzo- soprano Susan Graham should be canonized.

The 49-year-old Graham's singing résumé reveals an intense desire for tackling a wide range of roles. These range from the silky lilt of a French song, to the bracing edge of modern opera, to the crystalline sheen of the English baroque.

It is with the latter that Graham will appear with Philharmonia Baroque at the Mondavi Center's Jackson Hall on Saturday.

The highlight of the all-Purcell concert will surely come when Graham sings the role of Dido, the Queen of Carthage, in Henry Purcell's "Dido and Aeneas."

The tragic opera, to be performed in concert format, will be conducted by Nicholas McGegan in a program that also includes "Suite From Abdelazer" and the Chacony in G minor. Baritone William Berger and soprano Céline Ricci will also appear.

For Graham, singing the role of Dido is like tapping into a groundswell of musical purity.

"Singing the role will be like drinking a long, cool drink of fresh spring water when you've been surrounded by milkshakes," said Graham via cell phone from New York City, where she lives.

The milkshakes, for Graham, are an apt metaphor for the tasty roles she has been performing lately, which include the likes of Ravel, Mahler and Richard Strauss. When Graham appears at the Mondavi she will be fresh from a recent role, as Count Octavian, a teenage boy, in Strauss' "Der Rosenkavalier" at the Metropolitan Opera.

"I love doing 'Dido and Aeneas' because it feels so pure and honest," she said.

It is a work that feels refreshingly current despite the fact that it dates back to 1689, said Jeffrey Thomas, longtime artistic and music director of American Bach Soloists and a baroque specialist who has conducted the work several times.

"The combination of dramatic intensity and dramatic realism that is the essence of this work … remains as palpable now as it must have three or four hundred years ago," Thomas said.

Big emotions are a given in Dido's tragic tale of love, betrayal and madness. And, as far as emotional musical moments go, few arias can top Dido's final lament in the third act. It is an aria that seals her fate.

The smaller orchestration of baroque opera gives Graham the benefit of not having to push her voice to be heard over the orchestra.

"Singing 'Dido' is not all just about volume, or just about range; it's also about color and expression."

And the icing on the cake, for Graham, is that she gets to sing in her mother tongue.

"Singing in your native language has a special flavor to it because you don't have to go through the process of translating in your head," Graham said. "There is an immediacy to the emotion of the text."

Operas in English that predate the 20th century are not many. Purcell's 17th century work is one of the few English operas to enter the repertoire. English opera would have to wait until the 20th century, and the ascent of Benjamin Britten, to see one of its operas enter the repertoire.

" 'Dido' is the earliest great English opera and manages to have tragedy, comedy, high drama and light dance music all in the space of 50 minutes," said Philharmonia Baroque's McGegan. "As such, it's more like Monteverdi's 'Poppea' than the operas of Handel. For me it is one of the greatest pieces of English music."

"Dido and Aeneas" is a work McGegan knows well. He conducted and recorded it in 1994 with the late, great mezzo-soprano Lorraine Hunt Lieberson.

Graham credits 13 years of study on the piano as laying the foundation that allowed her to sing with a startling clarity, and with the facility to transit from French song to the baroque easily.

"I was convinced I was going to be a pianist, but singing took ahold of me and never let go," said Graham.

Born in Roswell, N.M., Graham spent her teenage years away from the cultural mainstream, especially in Midland, Texas.

When she moved to New York City to attend the Manhattan School of Music, she quickly realized many of her peers had grown up going to the Metropolitan Opera every week.

"I felt I was really deprived and that I had a lot of catching up to do," she said.

"But, in a way, those of us who come from small towns all over America come to that world without a sense of expectation … it's sort of like a clean start."

Call arts critic Edward Ortiz, (916) 321-1071.