Consonant/dissonant
This example from a string quartet by Haydn uses mostly intervals that do not clash – it is very consonant:

This example from a string quartet by Bartok uses lots of clashing intervals – it is very dissonant:

Diatonic/chromatic
This example from a symphony by Mozart uses only the seven notes taken only from the scale – it is diatonic:

This example from an opera by Rimsky-Korsakov uses lots of notes that are not taken only from one scale – it is chromatic:

Major/minor

A Haydn piecein a MAJOR key:

A Haydn piece in a MINOR key: