Quiet please. Lupu, Nelsons, and the Boston Symphony Orchestra play Mozart.

Andris Nelsons conducts the Boston Symphony Orchestra with pianist Radu Lupu, 20 April 2017. Hilary Scott photograph

One might expect that a comparison of two strikingly different Mozart works—a small-scale concerto, with modest forces, and a completely packed stage for the Requiem—would be a study in contrasts. 

In fact, given the approach that Boston Symphony Orchestra’s music director Andris Nelsons took Thursday evening at Symphony Hall, the two works were remarkably similar.

Much of that had to do with the piano soloist, Radu Lupu. Lupu has decades of distinguished performances to his credit, alliances with the greatest orchestras, and recordings of most all of the standard piano repertory. That reputation does not stem from performances like this.

Nelsons used about the smallest orchestra possible (6/6/6/4/2, winds, trumpet, timpani). That was likely Lupu’s doing, strange as it may seem, given the dynamic onstage. 

It started soft and slow, and stayed there. That wasn’t the problem. This concerto, as inventive as mature Mozart can be, certainly can handle such ideas. Every note got lingered over. Not all of them with care. 

Lupu seemed strangely indifferent onstage. He has always had an off-hand manner, but this was extreme—as if he wanted to be elsewhere. He did, however, conduct those few times the left hand was unoccupied, and gave a curious thumb’s up to Nelsons on a couple occasions—as if the maestro had gotten the instructions right.

It’s a gorgeous concerto, taking you to places only Mozart can. Delicate doubling of the piano with the oboe and clarinet in the second movement bring a warm intimacy to that movement. The theme and variations finale—there are six or eight variations, depending on how you count them, with a couple being double variations—had life, unexpected shifts, deeply Mozartian interplay.

Lupu seemed above it all. He played his own cadenzas (first and third movement—the latter a very brief one). There had to be some missed notes in the first one, or else some curious ideas. He played below audible range sometimes, which is fine if it’s intentional, but here just seemed careless.

Mozart’s Requiem was thoroughly well staged, on the other hand, with four matched soloists and the Tanglewood Festival Chorus singing their hearts out for guest chorus conductor James Bagwell. 

Lucy Crowe (soprano), Tamara Mumford (mezzo), Ben Johnson (tenor) and Morris Robinson (bass) proved a blended quartet, all lyric, all strong, and, in the multiple ensemble sections, all collaborative. An SATB canon to open the Benedictus proved the strongest example. 

The work, which of course Mozart could not complete, has two different feelings: up to the Lacrimosa (where Mozart stopped), all invention, unusual sacred writing, and great depth; and after that, here in Süssmayr’s completion, as solid, unfussy and unimaginative as Mozart is not. 

Nelsons was brilliant. The work belies its large forces—it really is intimate and thoughtful, with many sublime touches. Unison strings, doubling of the chorus’s coloratura in the final fugue (Lux Aeterna), was only one example of Nelsons carefully drawing details out of his players.

CADENCE: Claude Frank gave the first performance of the C minor concerto with the BSO in 1959, under Munch. Why did that take so long? Conversely, Requiem was performed in April, 1888. Mozart left no cadenzas for this work. Brahms and Busoni wrote some, and last week’s soloist, Mitsuko Uchida, has beautiful ideas about the cadenzas as well. Lupu was the Van Cliburn competition winner in 1966. He has made many BSO appearances—the first in 1977—predominantly playing Mozart. This program repeats this afternoon and Saturday evening: bso.org; 888-266-1200.