Because it is so rarely heard as a solo instrument, it is easy to forget how lush the viola's tone is. Cynthia Phelps made sure no one overlooked this at her recital at the Phillips Collection yesterday.

Playing pieces by Bach, Enesco, Beethoven and Hindemith, she focused on warmth and sweetness, finding the most success with Beethoven's Seven Variations in E flat Major on a theme from Mozart's "The Magic Flute," where she concentrated on creating a sense of vocal line. It was evident, here, that she was listening to herself and that she was imposing as much intensity on soft passages and longheld notes as she was on the more active and energetic phrases.

The Bach Sonata No. 3 in G Minor was pretty but without a sense of direction. Phelps moved through it with a matter-of-fact accuracy that projected Bach's intellectual contrapuntal aspect clearly, but missed his Italianate way with weight and momentum. This music requires as much commitment to a true legato phrase as to true rhythmic integrity, and at the moment, a real legato is not a strength of Phelps' technical repertoire.

Both Enesco's "Concertpiece" and Hindemith's Sonata Opus II No. 4 are rooted in an opulent, romantic tradition, and Phelps approached them with intelligent musicianship. She neither went for the big statement nor focused on details, preferring instead to present a balanced and contained reading, and this worked very well.

Phelps, who won first prize in the 1985 Friday Morning Music Club International Competition, was accompanied by her sister Sheila Phelps Johns, who won that same honor in 1982 and who accompanied with stylish authority.