What is the difference between tonality and key in music?

Question

I've heard that tonality and key are not the same thing and I was wondering what the differences are? Would love it if somebody could clarify these terms, thanks!

Answer 1

There are (at least) two completely distinct senses of the noun 'tonality' in English -

The first sense of the word 'tonality' just means, in general, 'the types of harmonic relationships and motions' in a piece of music.

If this is the sense of the word 'tonality' that you mean, then we can say that a key is a way to describe the tonality of a piece of music from the perspective of the major/minor system. This might be appropriate for some types of music. For other types of music it might less useful or apprpriate to talk about 'keys'. We could say that this sense of the word 'tonality' is more general; 'key' is more specific.

The second sense of the word tonality is less well-defined - I'll refer you to this question. This sense of the word refers to a subset of types of harmonic practice, though exactly which subset depends on which definition you agree with! You could say that tonality (second meaning) is a type of tonality (first meaning), and that key is arguably an aspect of tonal tonalities.

I'm not deliberately trying to be confusing - but if anyone thinks I've missed out any definitions of 'tonality', I'll add them.

I'll ignore the definition of key as 'something you press on a piano'.

Answer 2

Tonality is the intuitive perception of any Tone. A Tone has three aspects: Pitch,Timbre and Dynamic state or Tendency. For example if we intuit middle C on the piano as the Tone 'Ti' then the Key or Tonality is 'D-flat' since D-flat is obviously 'Do'.