Dominant 1. A function. The fifth note, or chord of any scale, or position of a chord, indicated ‘V’, or ‘5’. Functional Names of Scale Degrees
2. An identity. A chord with characteristic intervals of a major 3rd and a minor 7th; a tritone, indicated as ‘x’, its identifying symbol. It may be used anywhere and not limited to the 5th position of a scale. ‘V7’, is a function, not an identity indication.