There was plenty of fire power on hand last night for the Rhode Island Philharmonic, with Jon Kimura Parker at the keyboard. But really it was the music that deserved the biggest hand, as the orchestra came up with one of the classier couplings in recent memory — Sibelius’ radiant Fifth Symphony up against the First Piano Concerto of Brahms.

The Brahms is heard often enough, although it has been almost 13 years since the Philharmonic last tackled it. But the Sibelius, a striking work unorthodox in nature, has never been performed by the Philharmonic.

If there were a theme to the evening it would perhaps have been composers struggling with form. Both works had painful births. Sibelius reworked the Fifth numerous times and eventually fused the first two movements, the opening Preludio and Scherzo. Brahms, on the other hand, started out writing a two-piano sonata and toyed for a while with a symphony, before deciding on a concerto.

In both cases the composers came up with masterpieces.

Conductor Larry Rachleff called the Sibelius a “staggeringly wonderful, unconventional piece,” full of “hidden messages.”

And his observations were borne out in the fine account he gave of the score, one of the more inspired performances the orchestra has given in recent memory. Rachleff let the opening themes blossom nicely, then eased into the animated scherzo without showing as much as a seam.

There was tremendous contrast, too, with lush outpourings from the brass set against some of the most hushed string work. Much of that came in the soothing Romanza, where the theme is at one point uttered in delicate pizzicato phrases. And in full passages the strings sounded warm.

Then came the glorious finale, with its glowing main theme and striking coda of disjointed chords that sound like hammer blows separated by yawning pauses.

Rachleff and the orchestra should be commended for holding such a ticklish piece together so well, for keeping all those tricky transitions in check, and getting to the point of this unusual score.

After intermission, Parker joined the orchestra for the Brahms, one of the great pieces in the piano repertoire, bested perhaps only by the composer’s B-Flat Concerto.

Parker and Rachleff — both faculty members at Rice University, in Houston — teamed up in a performance of this work back in the fall in San Antonio, Texas, where Rachleff is also music director. And their previous work together appeared to pay dividends last night, making for a tight, responsive rendition.

The driving finale perhaps fared the best, with Parker bouncing out of his seat to knock off those thundering chords near the close of the movement. The opening movement, by contrast, was a little one-dimensional, without the shading found in the melting slow movement.

That’s where Parker and the orchestra matched one another perfectly, where the piano just seemed to grow out of the string parts.

cgray@projo.com