John Albertson is a self-avowed high school truant and music school dropout who would gladden the heart of any reasonable parent.

At 26, he is about to enter Catholic University's graduate program in music. His ambition is to compose serious works for the guitar and, eventually, orchestra.

"I used to play hookey in the 10th and 11th grades," the quietly humorous Albertson admitted. "I just wanted to practice my guitar as much as I could."

As for dropping out of the prestigious Juilliard School of Music in New York, Albertson made that decision because the school didn't offer a guitar major.

"I went to Juilliard for theory, music history, ear training and composition studies," he said. "Then in 1975 I was accepted at Catholic University, where I received my bachelor's degree."

Albertson came to the guitar through somewhat roundabout circumstances.

"Actually, I wanted a set of drums more than anything when I was 11 years old," he said. "But we always lived in apartments and my parents wouldn't let me have them. (One Christmas) there was a pair of bongo drums under the tree, which of course didn't nearly meet my expectations.

"Then my father took me out to the car and opened the trunk and told me to look inside. All I could say was, 'It's only a guitar.'"

Albertson taught himself for a year, using song books to learn chords and to read music. Then he began formal lessons, including five years of study with Anthony Norris, now a teacher at George Washington University.

At present Albertson is preparing for a lengthy recital in November at Catholic University. It will be his audition for his graduate studies, and the judges will hear a range of music -- Renaissance pieces, romantic works by composers such as Mendelssohn and modern works such as Ravel's "Pavane for a Dead Princess."

In addition to his studies, Albertson teaches 30 private students, some in the studio of his Arlington home, others in a Falls Church guitar shop.

"I am a member of the Baha'i faith," Albertson said. "You might say it's the central part of my life. I try to apply Baha'i educational principles to my teaching.

"For instance, if a student has 10 qualities and nine of them are bad, then I concentrate on the one good quality and try to develop that.

"It makes the student feel more worthwhile as a human being and encourages the positive aspect of his work.

"For instance, I have young students who want to learn hard rock," he said.

"I make sure that that part of the student's interest is fulfilled, but I also teach them great works. The main ingredients I teach are great classical and jazz music. That is the staple diet.

"Then, for each assignment they complete, I let them pick one on their own. I had one student who really did go from rock to Bach," he added with a laugh.

Albertson has a long-range goal in life: "I hope to get my doctorate in music theory, and then I would like to go pioneering in some smaller country, he said.

"I would like to find some small country, perhaps in South America, where I could have a base in a university and still concertize."

For the past five years, Albertson has studied the piano because, he explained, "You must know the keyboard if you're going to master musical theory."

Among the compositions he plans are musical settings for Babh'i writings. "I wrote on a cappella choral piece called 'The Hidden Words,' which I conducted in 1979 at the University of Maryland," he said.

As evidence of the satisfaction he derives from playing and teaching the guitar, Albertson explained, "It is a tenet of my faith that music is food for the soul." CAPTION: Picture, John Albertson uses Baha'i principles when he teaches guitar. $1By John Dwyier For The Washington Post