Volume substituted for control and mannerisms for style in a disappointing performance at the Pan American Union last night by soprano Evangelina Colon.

Though attractive to look at and discriminating in her choice of music, Colon simply did not have the means to handle her program. Whenever she moved out of the middle of her range, serious problems arose. Upper notes were approached tentatively; pitches were frequently slid into or never quite achieved. On the lower end of the scale her voice, not especially resonant in any case, sometimes gave out, losing all tone.

In the first half of the recital Colon was so preoccupied -- and rightly -- with technical problems that none of the music's inner meaning came through. An opening Mozart selection was leadenly pharased, a lovely quartet of Brahms songs suffered from limited dynamic and vocal shading, and the elegance of a series of French songs never materialized.

While far from free of technical difficulties, the second half, centered on works from Latin American composers, went better. Colon had loosened up a bit vocally and, in addition, seemed to feel much closer to her material. She gave her most effective interpretation of the evening in an engaging set of songs by Hector Campos-Parsi, a composer from her native Puerto Rico.

The closing works, including a nationalist Puerto Rican song and a torch ballad, though rather tritely written, clearly won the hearts of her audience, which sounded hearty approval of both.