A collection of two or more notes played simultaneously. Root position refers to the basic organisation of the tonic, third and fifth degrees of the scale (triad). A first inversion chord contains the same notes but starts on the third and a second inversion chord starts on the fifth. Chords can have added notes such as a seventh, and can be identified and described using Roman numerals (e.g. V, I) or chord names (e.g. C Major).