A reel is an object around which lengths of another material (usually long and flexible) are wound for storage. Generally a reel has a cylindrical core and walls on the sides to retain the material wound around the core. In some cases the core is hollow, although other items may be mounted on it, and grips may exist for mechanically turning the reel.

The size of the core is dependent on several factors. A smaller core will obviously allow more material to be stored in a given space. However, there is a limit to how tightly the stored material can be wound without damaging it and this limits how small the core can be.

Other issues affecting the core size include:

With material such as photographic film that is flat and long but is relatively wide, the material generally is stored in successive single layers. In cases where the material is more uniform in cross-section (for example, a cable), the material may be safely wound around a reel that is wider than its width. In this case, several windings are needed to create a layer on the reel.

Russ Barenberg (born October 8, 1950) is a Grammy-nominated American bluegrass musician.

Barenberg began playing guitar at age 13, taking lessons from Alan Miller, whose brother John Miller Barenberg he would later play with. His style was heavily influenced by the flatpicking technique of Clarence White. He attended Cornell University and met Pete Wernick there in 1968. Together they joined to form Country Cooking, who released two albums of bluegrass before breaking up in 1975.

In 1975 Barenberg briefly began playing electric guitar with a jazz rock group, Carried Away. Late in 1975 he quit playing music, but returned in 1977, moving to New York City to play in the group Heartlands. This group also played backup on Barenberg's debut solo effort, Cowboy Calypso, in 1980. He then moved to Boston, teaching at the Music Emporium in Cambridge. Here he played in the groups Fiddle Fever and Laughing Hands.

In 1986 Barenberg moved to Nashville, where he has played often with Jerry Douglas and Maura O'Connell, and done much work as a session musician with Béla Fleck, Hazel Dickens, Mel Tillis, and Randy Travis, among others. He has released several instructional videos.