A review of the Smith Sisters in yesterday's Weekend section incorrectly listed their concert date at the Birchmere. It is tonight.

MERLE WATSON, Doc Watson's son and an underrated guitarist in his own right, died in a tractor accident last year while producing the Smith Sisters' second album, "Mockingbird." The album's title song features lyrics by Debi Smith to an old instrumental written by Merle. With its high, lonesome vocal harmonies by the Falls Church sisters, its lead guitar by Merle and its theme of a departed singer, the song is the perfect tribute to the late guitarist.

Merle Watson's influence is felt throughout the album. Debi Smith displays a new knack for writing strong country-folk melodies in the Watson style for catchy up- tempo songs such as "Little Girl's Heart" and "I Got, You Got," which stand up well next to the traditional country standard "Sweet Sonny South." Of course, it helps that the two Watsons are picking guitar and Sam Bush is on fiddle.

The sisters' affection for Irish music can be heard in Megan's lovely penny whistle leads on Debi's "Tell Me More" and "Walking Man." The album's flaws include a certain lack of aggressiveness in the arrangements and questionable choices of so-so pop-folk songs written by Judy Collins, Joan Baez and Karla Bonoff.

THE SMITH SISTERS -- "Mockingbird," (Flying FIsh, FF370); appearing with Pete Kennedy and Mike Stein at the Birchmere on Friday