Joe Bushkin's childlike glee on jazz piano

Jazz pianist Joe Bushkin is back - for good, he insists. After a long and successful career as a player in many Dixieland groups and with the big bands of Artie Shaw, Tommy Dorsey, and Benny Goodman, among others, as well as with Bing Crosby and legendary jazz singer Lee Wiley, Bushkin went into retirement in the late '50s. He moved to Hawaii, and later to California, where he raises thoroughbred horses.

But Joey Bushkin couldn't stay ''retired'' forever. The musical urge wouldn't leave him alone, and this self-taught pianist began a gradual reentry into the music scene in 1976.

At a recent engagement with his trio, the diminutive Bushkin, who also sings an occasional tune in his charmingly gravelly voice, played with a joie de vivre and an almost childlike glee that brought to mind a little piece of the lyric to his famous song, ''Oh, Look at Me Now'': ''I'm so proud I'm bustin' my vest!''

Bushkin was ably backed by Jake Hanna on drums, Phil Flanagan on bass, and (the night I caught the group) another self-taught legend, guitarist Johnny Smith, who for quite a few years had been keeping himself as well hidden as Bushkin.

Everyone seemed to be having a great time. Bushkin, despite his long absence from the professional music scene, had no trouble getting around the keyboard. In an interview between sets with Bushkin and Smith, I asked Joe how he manages to keep his technique in shape as well as he does.

''It's very simple. If you're a classical pianist you have to practice, because everything has to be precise. In jazz, if you've been playing as long as I've been playing, or as long as Johnny Smith has been playing, it's like riding a bike. I would be concerned only about getting slightly tired, but the notes are all there. If I couldn't play what was going through my mind, I'd just quit playing the piano.

''When I haven't played for a while, my ideas are very fresh. If I'm playing every night - well, even a train stops, you know. I get a little bored.''

Bushkin joined a band when he was still a boy - ''to make enough money to have the excuse of not going to high school. My dad said, 'If you quit school, you can forget it - no allowance!' '' Bushkin takes pride in his lack of formal training, and praises his friend Johnny Smith for having taught himself, too.

''Johnny's got the idea, being self-taught. That's the whole idea.''

Adds Johnny, ''Back in our days, most all jazz musicians were self-taught. There was no jazz music curriculum in the schools. One thing that always amazes me - we go to a school to do seminars, or to teach, and the No. 1 question we get asked by our young people is, 'How do you improvise?' Joe and I, until they put jazz into the education system, never heard anybody say, how do you improvise?''

Joe mentioned that he was recently asked that question in an interview at his hotel. ''I said, 'No one has ever asked me that, so this may take a minute or two while I order room service, while I decide how I improvise!' So the interviewer started to improvise what he wanted to eat, and I started to improvise what I wanted. See, there you go, we were improvising! So I said, 'You see, before I mentioned lunch, you weren't thinking of lunch, were you?' He said , 'No,' and I said, 'Well, that's the idea - blank your mind out so you can put something in it - that's improvising.' ''

Johnny and Joe proceeded to joke about what it's like to play only once in a while instead of all the time. ''Now that I'm in my 'anecdotage,' '' quipped Joe , ''I play maybe once a year. Johnny plays three or four times a year.'' Aside to Johnny - ''You ought to cut that out, you'll burn yourself out!'' And, ''Johnny always says his fingers feel like art-gum erasers, and so do mine, actually!''

Joe and his wife have their horses, and Johnny? ''In 1960 my wife and I opened up a music store in Colorado Springs.'' He has also taught at the University of Northern Colorado. ''I started off their guitar curriculum a few years ago. I taught there for a whole year, one day a week.'' Smith, like Bushkin, used to play all the great old jazz clubs here - the Embers, Birdland, and so on. Says Smith, ''I had my time in New York - the good old days.''