New music mixed with old in Friday evening’s concert by the period-instrument ensemble First Lutheran Church in Boston’s Antico Moderno. Led by founder Bálint Karosi at the harpsichord, the ensemble offered an intriguing hour alternating17^th-century Italian chamber sonatas with contemporary works employing the same combinations of old instruments. The group, which in this incarnation also included Heloise Degrugillier (recorders), Edson Scheid (violin), and Jacques Lee Wood (cello), will repeat the program Sunday afternoon in the Norway Pond series at Hancock, New Hampshire. The Hungarian-born Karosi, until recently organist at First Lutheran, is now cantor at St. Peter’s Lutheran Church in Manhattan.

The evening’s title, “Stylus Phantasticus,” more properly refers to the improvisatory music of German Baroque composers such as Buxtehude for organ and other keyboard instruments. But it was apt for the somewhat earlier selections by five Italian composers which, although little-known in mainstream musical circles, have long been standards in the historical-performance world. None of this music was actually composed for precisely the combination of instruments heard Friday night. But the two new works were written specifically for the group, which in its short history has made a practice of commissioning compositions for “old instruments.”

But these have sometimes been written in tired neo-Classical (or neo-Baroque) styles, as in Lester Trimble’s Four Fragments from the Canterbury Tales, or Persichetti’s harpsichord sonatas. Or they combine one or two early instruments, such as the harpsichord, with modern ones, as in Elliott Carter’s Sonata for harpsichord, flute, oboe, and cello.

The sound and playing technique of Baroque winds and strings also differ substantially from those of present-day instruments, however. The “moderno” portion of Antico Moderno’s programming takes advantage of sonorities which can be produced only by the gut strings and other “antico” features of historical instruments.

My single negative critique of Friday’s concert is that it was too short; it comprised barely 60 minutes of music, and few of the individual compositions seemed quite long enough to stand on their own. Several of the early-Baroque pieces, originally intended to serve as preludes or interludes during religious services, might have seemed more substantial if grouped into pairs. And the wonderfully imagined sonorities were just getting interesting when Eun Young Lee’s “Gil,” one of the two newly commissioned works, reached its understated conclusion.

The playing was nevertheless superb. I was worried to find the players still rehearsing when I entered the hall a few minutes before the scheduled starting time. But the playing was assured and the ensemble flawless, even in the frequent changes of tempo and tricky transitions of these early-Baroque examples.

The program opened with Sonata 8 by Giovanni Battista Fontana, from a posthumously published 1641 collection, and Sonata 10 from the second of two sets first issued during the 1620s by Dario Castello. Both typify their time in consisting of numerous short, contrasting sections. But Fontana’s was originally for two violins and continuo, Castello’s for two unspecified treble instruments and continuo plus “bassoon or viola.”

There was no loss in assigning one of the upper parts of both sonatas to recorder, especially given Degrugillier’s seemingly effortless virtuosity. Nor could anyone take serious issue with Wood’s equally fluency on cello, instead of some precursor instrument, or with the use of a small but bright-sounding Italian harpsichord to provide continuo, in place of the organ, that probably would have accompanied most early performances. But I would have liked to hear a bit more contrast between the two, which differ not only in their intended scoring but in personality. Fontana tends to maintain a certain gravity and breadth of phrasing despite his florid early-Baroque melodic writing. Castello, on the other hand, is prone to sudden, surprising changes of speed and character, dramatically juxtaposing sharply contrasting ideas. That said, this interpretation was at once as dashing and as polished any I have heard of either, although perhaps not every quick section needed to start fast and then get even faster.

The first of the two new commissions, William Cooper’s “Sonata a quattro” (Sonata for four, a common Italian Baroque title), was conducted by the composer. He clearly understands the instruments, being director of the Early Music Ensemble at the University of California at Davis, where he is also a doctoral student in composition. In prefatory remarks he described these roughly ten minutes as a confrontation of two styles, one “more contemporary” than the other; these do “battle” and then “reconcile” at the end. I wasn’t sure I heard the reconciliation. But the contrasts were clear enough, although I sensed a neo-Classic element throughout, even in sections that featured flutter-tonguing (rapidly repeated notes) from the recorder, alongside other new-ish techniques. The less “contemporary” passages occasionally suggested the mid-20^th-century modernist counterpoint of American composers such as Walter Piston and Aaron Copland. But these never sounded derivative, and they alternated unpredictably yet gracefully with the more motoric contrasting passages.

At the center of “Stylus Phantasticus”stood two solos. Biagio Marini’s Sonata “per sonar con due corde,” from his path-breaking Opus 8 of 1629, stands as the first collection to contain significant music for solo violin. Accompanied only by the ever-inventive Karosi at the harpsichord, here the Brazilian-born Scheid demonstrated why he is both musically and technically one of the most assured and accomplished of today’s younger period violinists. Potentially a chaotic jumble of contrasting snippets, Marini’s sonata came across as an eloquent monologue, comparable in effect to one of the composer’s monodies for solo voice. Only one short passage is actually “to be played on two strings,” that is, as a series of chords. This section was suitably lively and dance-like, but several quiet, vocally conceived passages moved us more. (Disclosure: Scheid was a student in the class in historical performance that I teach at Juilliard.)

An “improvised Fantasia and Ciaccone on the electro-acoustic clavichord” followed. Here Karosi played alone on a recently acquired instrument built by the Montreal-born maker and player Renée Geoffrion. The clavichord, originally a very quiet stringed keyboard instrument of the Renaisssance and Baroque, is here enhanced by an electric-guitar-type pickup. The device did not impress me with its somewhat jangly but otherwise unmodulated sound. Nor did Karosi’s improvisation sound like one, but that is hardly a negative criticism. For the poise and the clear, skillful harmony with which he played might as well have been those of a written composition—even if the style tended to migrate from 17^th-century Italy to something closer to early eighteenth-century France or Germany.

My outstanding discovery of the evening was Lee’s “Gil,” for the full ensemble and again conducted by Wood. As explained by the composer, who teaches at Boston Conservatory, the title is a Korean word meaning “road” or “path,” with the same metaphoric implications as its English equivalents. In “Gil” I was struck by the imaginative use of the ensemble’s distinctive sonorities, which included both harpsichord and amplified clavichord. In one passage that combined quiet violin and cello harmonics, Degrugillier’s tenor Renaissance recorder sounded almost like a shakuhachi, the Japanese smoked-bamboo flute. But the composer told me afterwards that she hadn’t originally intended the piece to recall Asian instruments. All the same, the utterly contemporary writing for these five mostly historical instruments led me hoping to hear more than what the piece’s five minutes or so could make of them.

The expressive closer, Giovanni Paolo Cima’s “Sonata a tre” (the very first trio sonata) and Antonio Bertali’s Ciaccona for violin and continuo, arrived in an arrangement that had the recorder alternating with violin on the top part, with pizzicato cello joining the harpsichord on the continuo line. I was probably the only member of the audience who did not find this delightful, but no one could complain that it lacked precision or panache.

David Schulenberg’s The Music of Carl Philipp Emanuel Bach was published in 2014 by the University of Rochester Press. He has also written books on the music of W. F. Bach and the keyboard music of J. S. Bach, as well as the textbook Music of the Baroque. A performer on harpsichord, clavichord, and fortepiano, he teaches at Wagner College and at the Juilliard School in New York City. His website is here.