A decade back a great deal of excitement began to brew over alto man Frank Morgan, the suddenly rediscovered Charlie Parker acolyte who first emerged in the 50s but spent much of the next 30 years in prison. During all the hoopla, though, knowledgeable jazz fans had to send at least a passing thought in the direction of Herb Geller. In the 50s, playing with top west-coast bands led by Shorty Rogers and Bill Holman, Geller emerged as one of the brighter lights on the beachfront--savvy, passionate, and cool--frequently working with his wife Lorraine, an equally talented pianist. But, like Frank Morgan, Geller would become all but invisible to American audiences over the next three decades. Lorraine died suddenly in 1958, and reports indicated that she took a big chunk of Geller with her; he continued to perform, but without the same spark, and his friend Stan Getz advised him to leave the country and mend his memories. Geller landed in Brazil and eventually Germany, where he remarried, and where he hooked up with one of that country's prestigious state-funded radio jazz orchestras (long before such associations had become common). Then, slowly, the occasional bit of news, and even an album or two, would drift back to the States, indicating that Geller's strengths had returned. These include his tone, which is full but not fulsome and retains a dry edge characteristic of his west-coast roots; his fluid technical facility, which sounds born of rather than grafted onto his bebop roots; and the ability to write catchy and even distinctive songs, often seasoned with a nicely aged pinch of 60s jazz rock. Having made his name as an improviser and composer in various German bands, Geller remains such a shadowy presence in this country that I for one never expected to see him in the flesh. Joining him on the front line is another powerful player who came of age in the 50s and 60s, trombonist Curtis Fuller. Fuller--a speed-demon alumnus of two exceedingly influential outfits, Art Blakey's Jazz Messengers and the Jazztet (led by Art Farmer and Benny Golson)--plays hot to Geller's cool, which the weather maps suggest as the ideal conditions for lightning to strike. Tuesday though next Sunday, August 20, Joe Segal's Jazz Showcase, Blackstone Hotel, 636 S. Michigan; 427-4846.