Regrettably, this summer’s Early Music Festival features only one composition by the great Johann Sebastian Bach (1685-1750), at least several too few. Last Friday, Musicians of the Old Post Road played his Harpsichord Concerto No. 1 in D Minor, BWV 1052, a work locally performed several times in several venues over the last decade. BWV 1052 ended a program that featured Bach’s largely unknown contemporaries, titled “Bach and His Virtuosi.”

Pierre Gabriel Buffardin (1690-1768), a virtuoso on the then new transverse flute, supplied the program opener, a Sonata for Three Instruments, played by flutist Suzanne Stumpf, violinist Christina Day Martinson, cellist Daniel Ryan and continuo player Michael Bahmann. I found the piece surprisingly strong, with rich harmonies, good instrumental color and even some Bach-style counterpoint. And the playing was not so bad either.

Guest violinist Cécile Garcia-Moeller then performed the Sonata in A Minor for unaccompanied violin by Johann Georg Pisendel (1687-1755) — himself a violin virtuoso. Preceding Bach’s great sonatas and partitas for solo violin, this work may have served as a model for them. As measured against the countless performances and recordings of the Bach works — which in a sense is unfair — Garcia-Moeller’s playing was a bit understated.

The program’s centerpiece featured mezzo-soprano Pamela Dellal singing in the Cantata Quel vago seno by the somewhat better known Johann Adolph Hasse (1699-1783). Stumpf, Ryan and Bahmann accompanied Dellal on their respective instruments. Otherwise an excellent vocalist, Dellal’s delivery seemed excessively opulent for music of this period.

Yet another “Johann” piece came next: the Concerto in D for flute, strings and continuo by Johann David Heinichen (1683-1729). This is a dazzler for the flute, but was written in the “new,” simple, Italian style, meaning pre-Classical and therefore the program’s weakest offering. Stumpf handled her material quite well.

In this performance, the Bach D Minor concerto appeared to be written for harpsichord and string quartet (two violins, a viola and a cello) — a minimal string accompaniment for this great work. That said, Musicians of the Old Post Road gave BWV 1052 a strong reading, with Bahmann’s harpsichord work both virtuosic and nuanced.

Sunday’s early-music program couldn’t have been more contrasting. It featured the four-performer Voice of the Turtle in Spanish repertoire from the ninth to the 16th centuries. Entitled “Roots and Shoots,” the program explored in depth Sephardic, Arab-Andalusian and Christian music then co-existing in Spain — even as those three cultures intermingled while living mostly in harmony.

The Turtle performers (the name actually referring to the turtledove) are Derek Burrows, Lisle Kulbach, Jay Rosenberg and Judith Wachs. Presently in their 29th season as a group, they all sang, while playing every imaginable period instrument. The music was exotic in every sense of the word. The performers were versatile in every sense of the word. The continuingly sizable Early Music Festival audience responded appropriately.