Yesterday at Lisner Auditorium, guitarist and tenor David Perry demonstrated what some of us have long suspected with no solid evidence: that an amplified guitar can be a musical instrument.

Several musical instruments, in fact. During a lunch hour concert in the "Lisner at Noon" series, Perry's "digital synthesis" guitar sounded at various times like an organ, a harpsichord, a flute and a string quartet -- even, occasionally, like a guitar. This instrument is still in its early stages of development, and the Lisner concert (well attended by Washington's leading guitarists) was its first public appearance.

"I've been thinking of calling it the 'orchestral guitar' or the 'David Perry one-man chamber ensemble,' " Perry said in a conversation after the concert. By any name, it compares to the average amplified guitar as a Rolls-Royce does to a pair of roller skates.

As its working title indicates, this instrument applies to the guitar some of the technology already associated with keyboard synthesizers. It looks and operates like a regular acoustic guitar, but plugs into a bank of computers that can take and store sound samples (flute, cello, thunderstorm, cat's meow, etc.) and then apply one or more of its stored timbres as a sort of overlay to the melodies and harmonies fed into it from the guitar. At its debut, the synthesizer's sound approximation was impressive, though it left room for growth.

Many pop and folk performers can sing and play the guitar simultaneously, but this combination of talents occurs rarely in classical music. In a song as complex and stylistically demanding as Gluck's "Che faro` senza Euridice," it is usually considered challenge enough to handle the Italian text, the melody and the early classical style without also providing your own accompaniment. But Perry accompanied himself quite ably on a standard acoustic guitar while singing the tragic lament fluently, with excellent tone and precise diction.

The short concert covered the gamut from the guitar of yesterday to the guitar of tomorrow. It opened with a giant theorbo, or archlute, on which Perry accompanied himself in several Elizabethan songs and also played an instrumental fantasia.

On the guitar-synthesizer, he gave a well-paced, richly textured performance of Pachelbel's Canon, a "Jesu, Joy of Man's Desiring" in which his guitar sounded remarkably like an organ, a "Sheep May Safely Graze" transformed into a love song by his own set of words, and a well-sung, delicately accompanied Gounod/Bach "Ave Maria." It was about as much music as one man can make in 45 minutes.