During an internship I got assigned to shade a Bass-guitar and got free range on what material to create. I decided to make an iridescent material that changed in-between green, purple and blue when viewed from different angles.
The model is not mine but bought from Turbosquid
The diffuse color is a simple set of two colors mixed using a falloff node to create a Fresnel effect, mixed with the stripe pattern which was basically a noise map. The reflective color was a gradient ramp node using the three different colors and using another Fresnel falloff node as a source map, this created the iridescent effect. To create the glitter effect I used a simple noise-map for a bump and reflection gloss. I mixed the result with a pure metal/chrome material masked with another Fresnel falloff node.