Many classical pianists want to develop jazz piano skills because they have acquired: (1) an awareness of the importance of jazz as an art form; (2) an attraction to the sophistication and complexity of jazz music; (3) an interest in exploring contemporary music styles; and (4) a desire to become involved with a type of music which is viewed as enjoyable. This study addresses the need for a short course in basic jazz piano skills oriented toward the special interests, skills, and attitudes of adult pianists and attempts to determine if a mastery learning theory approach can be applied as the basis of instruction. A course designed on this principle has specific objectives and is organized into small, sequential units in which student mastery is carefully monitored. Based on a review of mastery learning theory, a five session, 15 hour course was designed, developed, and taught to two groups of four adult students. An evaluation of student achievement was conducted during 1985 and 1986. Results indicated that: (1) all students reached the mastery level of achievement on the posttest; (2) 75% of the students reached the predetermined mastery level of performance concerning seventh chords; (3) 88% of the students achieved mastery level in improvisation; and (4) all students acquired more positive attitudes toward their own improvisational ability. Tables and figures are included. (JHP)