SINCE HE'S never been comfortable with the term "New Age," and you can hardly blame him for that, let's just say that Mannheim Steamroller's Chip Davis creates "Old Age music" the new-fashioned way by retrieving instruments from the past and combining them with contemporary ones. As a result, recorders and harpsichords are likely to butt shoulders with electric guitars and synthesizers.

However, on "Yellowstone -- The Music of Nature," Davis freely appropriates a lot more than instruments from the past. Incorporated into this sprawling and often evocative orchestral homage to the great National Park are works by Vivaldi ("La Primavera"), Respighi ("The Pines of Rome"), Debussy ("Ballade") and Grofe ("Cloud Burst" from "The Grand Canyon Suite"), along with pieces that Davis previously included on Mannheim's popular series of "Fresh Aire" recordings.

By turns contemplative, stirring, effervescent and, alas, a bit sleepy and New Age-ish, the music -- often rustling with natural sound effects -- is performed by members of Mannheim and the Yellowstone Symphony, featuring the Cambridge Singers and musicians drawn from orchestras around the world. Like the park itself, the score isn't short on grandeur, but it's probably best appreciated at the kind of outdoor concert Davis will conduct this weekend.

MANNHEIM STEAMROLLER --

"Yellowstone -- The Music Of Nature" (American Gramaphone). Appearing Sunday and Monday at Wolf Trap.