This was Juanjo Mena’s first engagement at the NSO. (Michal Novak)

This week’s National Symphony Orchestra program is a mélange — nothing really going with anything else — but the debut of a fine guest conductor, an always-welcome soloist, and one of the most popular symphonies in the repertoire added up to a satisfying evening nonetheless.

Juanjo Mena, a Spanish maestro in his early 50s, is the music director of a provincial British orchestra, but regularly guest conducts all of the top U.S. and European orchestras; it’s odd that it took the NSO this long to engage him. At last night’s performance, his relaxed, collegial style gave the musicians involvement and empowerment, which you could see in their body language. They need, perhaps, more familiarity with each other, though.

In the Tchaikovsky “Pathétique” Symphony, he and the bassoonist didn’t seem to agree on the opening tempo, and the big, keening climax of the first movement was incoherent as the strings couldn’t be heard (All playing in unison!). The sloppy beginning of the march/scherzo could’ve been avoided if he’d conducted in four rather than in two, but perhaps it will go better tonight. Still, Mena’s warm, confident musicianship paid many dividends, and he should be brought back soon.

The concert began with a local premiere of “Auditorium” by Mason Bates, the Kennedy Center’s composer-in-residence, whose tenure was just extended for two more seasons. The work is a sort of dialogue, between past (Baroque music), present (the modern orchestra) and future (electronics). Bates, from the back of the stage on his laptop, mixed an electronically processed “Baroque ensemble” into the orchestral texture, which sometimes blended and sometimes disrupted.

Invoking earlier music is an idea as old as composed music itself, of course; everyone does it to one degree or another. But the first part of “Auditorium” just sounded gimmicky and annoying. Only in the middle section, when things settled into an “earthy groove” (per the composer) did the piece seem to be saying something rather than just being cute. As for the electronics, rather than “haunting” the orchestra players with shreds of music from the past, the apparition here was of a dystopian future in which their jobs were taken over by technology. Bates is an artist of real imagination and one who speaks to the next generation. I just hope his vision will stay grounded in what remains timeless about this art form.

Garrick Ohlsson then offered the Barber Piano Concerto, his rich, Brahmsian sound bringing quite a different color to the piece than its longtime proponent John Browning did. The concerto is a strong work, though with oddities — long stretches where the soloist is silent, a lyrical second theme that should’ve brought an infringement lawsuit from Shostakovich, and a slow movement whose plein-air texture cannot mask a limp sense of development. Mena and the NSO were not all together at all times, either. But there is much beauty in the piece, and Ohlsson’s magisterial playing carried the day, as it often does.

The program is repeated Friday, Saturday and Sunday.

Battey is a freelance writer.

Garrick Ohlsson played the Barber Piano Concerto. (Pier Andrea Morolli)