A harmonic vocalist, songwriter, and composer will be the featured artist at a concert and workshop sponsored by Harrison House in Joshua Tree. Timothy Hill will perform original songs and traditional material from America and India, accompanying himself on guitar in a concert at 8 p.m. Saturday, May 31. Tickets are $15 and are available from Joshua Tree Health Foods. On Sunday, June 1, from 10 to 2:30, Hill will offer a harmonic singing workshop that will explore the nature of the voice and throat singing. Tickets for the workshop, which will include a light lunch, are $45, and are also available at Joshua Tree Health Foods. For more information, call 760-366-4712.