WISCASSET — Sheepscot Chorus and St. Cecilia Chamber Choir will be offering  weekly virtual sessions starting the week of Sept. 13.

Under the leadership of Linda Blanchard and Sean Fleming, the sessions will include rehearsals, group vocal classes, as well as lessons in music theory and music history. Sessions may include advance rehearsals for an upcoming performance of the Verdi “Requiem.” Videos of the sessions will be available.

Members will have the option of rehearsing several seasonal selections to present a short concert of audio compilations in December. For more information or to register, visit sheepscotvalleychorus.org.

Two singers will be leading these lessons. Soprano Mary Sullivan has appeared as a soloist with numerous ensembles throughout New England. She has appeared as a recitalist at Bowdoin College’s Studzinski Recital Hall with pianist George Lopez, and has been a featured soloist for Opera Maine. Recent repertoire highlights include the Strauss “Vier letzte Lieder;” Handel’s “Messiah;” Pergolesi “Stabat Mater;” the Mozart “Requiem;” and Mendelssohn’s “Elijah.”

Sullivan is the artist in residence with the Oratorio Chorale, where she teaches vocal technique and coaches section sound and musicianship in collaboration with Artistic Director Emily Isaacson. Sullivan operates a private voice studio in Brunswick.

Bass-baritone John David Adams’ career has spanned concert, opera, recital and professional vocal ensembles. An active concert soloist, he has appeared with orchestras, choral organizations and musical ensembles across the country. Concert engagements in Maine and New England this season include a Monteverdi program with the Portland Early Music Festival; Magnificat settings by Bach, Telemann and Mendelssohn; Alice Parker’s “Melodious Accord,” Brahms’ “German Requiem;” and Handel oratorios “Messiah” and “Esther.”

He is a professional member of the New England-based Zenith Ensemble, Amethyst Chamber Ensemble, and Maine’s early music ensemble, St. Mary Schola. His diverse opera and stage credits range from Handel’s “Acis and Galatea” to Sondheim’s “Sweeney Todd,” in productions by Opera Boston, San Francisco Lyric Opera, Granite State Opera, Berkeley Opera, PORTopera (now Opera Maine), Apollo Opera, New England Light Opera, and Maine State Music Theater. He studied voice and opera at the Hartt School of Music and the San Francisco Conservatory of Music, and currently serves on the voice faculty of Bay Chamber Concerts Music School in Rockport. In addition to performing and teaching, he serves as Board Chair for OUT Maine based in Rockland.