Can you imagine Ravel's Sonatine being played on any instrument but piano? It takes some nerve to play transcriptions of much-loved music that is loved, in part, because of the way it falls on a particular instrument. But if you're a harp-flute-viola trio, you have to do something.

That something Monday night for Tre Voci was a mix of transcriptions and works written especially for this odd ensemble type whose oddness can be a virtue in the right hands.

It wasn't the only novelty for Monday's Philadelphia Chamber Music Society listeners. PCMS was dipping a toe into a venue new to it, Mitchell Hall at the College of Physicians, where musicians of the Philadelphia Orchestra have been playing chamber music for the last couple of years.

The space seems ordered up from Central Casting, old-world division, with its oils of formidable figures in dark robes looking down from high walls. It seats about 325, slightly less than the lecture hall PCMS often visits at the American Philosophical Society. (Both spaces are cheaper to rent than the 625ish-seat Perelman at the Kimmel.)

Tre Voci might have benefited from an acoustical shell to focus the sound, but the acoustic was plenty present, and the Mitchell has a warm resonance.

The trio brought with it a work of some occasion — the local premiere of Arabesque, commissioned from Japanese composer Toshio Hosokawa by Tre Voci in part with PCMS support.

The piece probably merits more than one listen. (Why don't groups follow premieres with a repeat of the same work later in the program?) But here it seemed limited, centering its action on a few pitches, ramping up tension, and then relieving it. Instrumental colors — where they overlap or dovetail and where they don't — were a focus. And then it seemed to go out on the wind.

The strongest performance of the evening was  in Arnold Bax's Elegiac Trio. Color is the star here, too, though violist Kim Kashkashian's sound was dry rather than ringing, a characteristic quite different from those of her colleagues. Flutist Marina Piccinini has a varied palette, but she has presence without sounding forced. Harpist Sivan Magen has an earthy energy; he is not afraid to explore the more percussive side of the instrument, often with great virtuosity.

In an arrangement for just viola and harp of the Suite populaire espagnole by Manuel de Falla, you wished Kashkashian could have reached deeper for the vocal origins of her part. A transcription for flute, viola, and harp of music from Prokofiev's Romeo and Juliet by Gilad Cohen was highly inventive — viola took the part of cellos and horns here, flute as violins there.

But it raised the same questions as the Ravel Sonatine, here in an arrangement by Carlos Salzedo. Why transcribe? There has to be a better reason than a dearth of authentic repertoire.

There are solid benefits to hearing the two-piano-and-chorus arrangement of Brahms' A German Requiem. The character of the music changes in a way that opens passages of understanding. It emerges somehow more modest and contemplative.

The most compelling reason for hearing the Ravel and Prokofiev in their altered states might have come from the charisma of the performers, but these musicians were only partially able to make their case. The rest of the time you pined to hear the original.