In musical terminology, an enclosure is defined as a type of approach note (or notes), whereby a target note - usually a scale or chord tone - is approached from both above and below, creating a quick sense of tension and resolution within a melodic line.

A physical enclosure usually refers to a confining, surrounding structure. Musical enclosures, on the other hand can actually be a freeing mechanism for the improviser (as opposed to our bagged little friend in the picture on the left).

Mastering the use of approaches and enclosures can greatly enhance the color and flavor of your melodic line.