Like many singer/songwriters of her lineage, Carly Simon has learned to stretch out her albums of new songs while still maintaining a steady release schedule.

She put out eight such albums in the 1970s and another four in the '80s.

But in the three-and-a-half years between 1987's Coming Around Again and 1990s Have You Seen Me Lately, there was a live album and an album of standards.

After that, Simon released a soundtrack and a "family opera" performed largely by others.

Letters Never Sent is her first new studio album in more than four years and only her second of the '90s.

In Simon's case, though, this is a good idea.

In the '70s, she tended to record too frequently, before she'd written enough strong material, resulting in uneven albums.

And with Have You Seen Me Lately, which was freighted with the concerns of middle age, she seemed to have written herself into a corner.

Letters Never Sent represents a fresh start, with little reference to aging, other than a song addressed to her late mother.

Rather, Simon has returned to passion as her main subject matter, confessing, "I can never be in love, I can only be in heat." She gives off that heat in many of the album's songs, though she doesn't quite fulfill the promise of the title, which implies lots of secret revelations.

Instead, there are mostly generalized songs of romance, delivered by Simon with a large cast of supporting players, including her children, a niece, and seemingly every musician who played on previous Simon albums.

It's an unusually coquettish performance for a woman of 49, and practically weightless.