Trumpeter Neal Berntsen has spent a lifetime mastering ensemble playing.

Trumpeter Neal Berntsen works on recording a CD at Carnegie Mellon University with the producer, Kevin Hartman, left, and Riccardo Schulz, recording engineer. Click photo for larger image. 'Trumpet Voices' "Trumpet Voices," also with music by Stravinsky, Biber, Reiche, Dannenberg and others, is available in select local record and bookstores and at www.fourwinds-music.com.

At present, however, the veteran orchestral player is struggling to blend in with himself.

The setting is a basement recording studio, one sunny afternoon this past August. Berntsen is sweating the details, trying to match his phrasing with that of a previously recorded track in a piece for multiple trumpets.

Bernstsen was the other trumpeter -- and would eventually be all the trumpeters in this ensemble piece. The idea was to see just how far technology can go in enhancing music-making.

"It has been an enormous project," Berntsen says. "I knew it would be big, but I didn't realize the scope of it. The final disc will be 70 minutes, but if I add up all the parts I play, it is five hours and 56 minutes to record! It is like putting out six CDs."

This month, Four Winds record label will release his disc, "Trumpet Voices: Classics for Trumpet Ensemble," recorded in a group of intriguing sessions last August. Berntsen, a member of the Pittsburgh Symphony Orchestra, invited me to witness the rara avis as the recordings were growing, one track at a time. I visited the afternoon he was recording works by Carl Ruggles, Leos Janacek and Johann Molter.

The project began when the label approached Berntsen about creating a disc, and he suggested trumpet ensembles. "[It's] a genre that has a lot of good stuff [yet] there aren't a lot of recordings," he says. It's not hard to see why: These works can require up to nine trumpeters. So he quickly proposed that he could play all the parts, too, and Four Winds loved the idea.

"They don't really need another Haydn and Hummel," Berntsen said.

As technology goes, Berntsen's expertise rests in brass, not silicon -- witness the six trumpets and 50 mouthpieces he brought to the recording session. However, he had a card up his sleeve when he suggested the multitrack album: Carnegie Mellon University.

In 2003, the CMU School of Music built a high-tech recording studio in the lower level of its College of Fine Arts building. It is a fine space, used in classes and for recording, and it is hot-wired to Kresge Hall on the first floor. As an instructor at the school, Berntsen sold the studio's director, Riccardo Schulz, on the recording, asking him to be the engineer.

Schulz and producer Kevin Hartman watch Berntsen through a video projector and communicate through a talk-back, while CMU undergraduate Richard Mason operates the recording equipment. It's complicated, but not half as complex as organizing an octet of trumpeters.

"And this way, Neal gets to play with his favorite trumpeters," says Hartman, laughing. He knows Berntsen from their days together in Chicago, where the trumpeter played for everything from the Lyric Opera of Chicago to commercials. Berntsen's recording work locally has primarily been with the Pittsburgh Symphony Brass.

"The idea of me doing all the tracks is that it gives the recording an evenness and a fidelity that is unique," Berntsen says "We recorded it that way, so when you are listening you are getting the imaging. Even for the pieces for two trumpets, I stood on one side of the stage for one and the other for the other part, so you can hear the trumpets in different channels."

Berntsen also uses different trumpets for different tracks, which adds to the auditory deception. Aficionados will appreciate that the CD liner notes list in detail every horn and mouthpiece he uses.

While multitracking is common in popular music, it has been slow to catch on in the classical realm. Wynton Marsalis tried it to mixed reviews in 1990 for a disc of Baroque trumpet music on Sony. Classical music institutions tend to resist innovation, but another reason multitracking has been slow to be accepted is that analog recording left a lot to be desired.

"With the advent of digital recording, they are able to isolate tracks better than they did before," Berntsen says. "In the past when you laid two tracks down together, there was a sense they didn't fit together. Now it is like you are in the same room and playing together like two different players."

It certainly sounds like it when, one by one, Berntsen adds tracks to Molter's Symphony in C Major for Four Trumpets. I don't think I could discern, without having been told, that the finished product was not four separate musicians. Schulz believes Berntsen's skills, honed in the hurried atmosphere of the studio, are what really made this multivoiced project work, not the newer technology.

"I would've never thought this possible, but he is such an incredible musician," says Schulz as Berntsen plays over the speakers. "If he misses it on the first take, he gets it on the second."

Almost on cue, Hartman says through the two-way, "Don't forget that last ritard." A few seconds later, Berntsen has nailed the phrase. In fact, these studio sessions are more intense for Berntsen than what is typical because he can't take a break. He's always on; he's the only one.

While Berntsen's playing is electric, there are still some kinks in the process. In the middle of recording Ruggles' quiet "Angels" for six trumpets, Hartman calls for a halt. It seems the multiple tracks accumulated too much background din.

"The noise built up in relationship to each trumpet," says Schulz, leading to more buzz than there would be for one take of six trumpeters. After some brainstorming, it's decided that the microphone has to be moved much closer to Berntsen to make it work.

It's not as if Berntsen is completely alone on the album. Several of the tracks require other instruments, and he's not attempting to play all of them, too. The PSO's Timothy Adams plays timpani for several pieces and William Caballero (horn) and Peter Sullivan (trombone) sit in on another.

Berntsen makes it clear that this is not meant to be a replacement for recordings by a full ensemble. He is just intrigued by what can come out of this process.

"It is very rewarding to play it," he says, catching his breath in between pieces. He can say that again -- and, simultaneously, again and again -- with this disc.