The Boston Early Music Festival Orchestra has been busy with this year’s festival opera, Handel’s “Almira,” but Thursday night at Jordan Hall, it focused on orchestral cosmogony. “The Birth of the Orchestra” provided snapshots of the turn of the 18th century, when that ensemble began to come into its own in European music.
Thursday’s orchestra was small by philharmonic-sized standards: strings, three reeds, occasional percussion, continuo keyboards. Nevertheless, the repertoire was designed to highlight instrumental mass. An Overture and Sonata from George Frideric Handel’s 1707 “Il Trionfo del Tempo e del Disinganno,” for instance, exploited concerto grosso practice, periodically shrinking the discourse down to primary-color solos — paired violins (orchestra director Robert Mealy and Cynthia Roberts), paired oboes (Kathryn Montoya and Gonzalo Ruiz), or a burbling organ (Avi Stein) — in order to amplify the punch of the full band charging back in. The Overture from Handel’s 1709 “Agrippina” decadently escalated such contrasts, coupling big/small, loud/soft switchbacks in dizzyingly abrupt shifts of tempo and rhythm.
In Arcangelo Corelli’s Concerto Grosso in D (Op. 6, No. 1), one could sense a shift toward power in numbers; even soloists’ flights were often beefed up with organ. An ad-hoc ballet assembled from various works of Jean-Baptiste Lully (complete with dancers Caroline Copeland, Carlos Fittante, Karin Modigh, and Mickaël Bouffard) went further, luxuriating in wide and well-spaced harmonies that took full advantage of the multiplied personnel.
The goal was sonic depth, boosted by an extra continuo player (Stein and Michael Sponseller combining organ and harpsichord, or doubling the latter) and lower pitch: As Mealy explained, the repertoire was chosen to match the tuning used for the opera, a full step below the modern 440 A. The higher tuning brought brilliance and clarity to the modern orchestra’s sprawl; the lower tuning let its Baroque forbear punch above its weight in richness — especially apparent in Georg Muffat’s “Dulce Somnium,” velvety sets of variations that revealed another orchestral attraction, the capacity for proliferating layers, with repeated phrases sprouting ever more flourishes.
Addition also figured in a Suite from John Blow’s “Venus and Adonis,” via percussion; in the Lully, percussionist Ben Grossman had provided discreet rhythmic emphasis, but Blow’s score used drums, cymbals, and tambourine as a garnish of special effects. All the program’s strategies turned up in Philipp Heinrich Erlebach’s 1693 Orchestral Suite No. 5, with the orchestra’s capacity for their permutation now in the foreground. Summing up the evening, Erlebach’s music rang methodical changes on the new ensemble’s toolbox.