Five Features of Tonality

"Conjunct melodic motion"*
Describes the characteristic short movements typically taken by tonal melodies. Up and down by 2nd, 3rd, and maybe 4th and 5th intervals. Typically not much more.

"Acoustic consonance"
Describes the degree to which sounds that are harmonizing tend to 'work' well together... have consonance. Like the a major third interval. An example of a harmony lacking consonance would be an augmented fourth.

"Harmonic consistency"
While this may sound like a similar feature to the previous one, it has more to do with structure than actual musical consonance. It describes whether the harmonies used in a particular piece of music tend to exhibit similar structure. Say, three note arpeggios on the second inversion... that would be a rather strict harmonic consistency.

"Limited macroharmony"
Take a section of a particular musical piece. The sum total of notes you hear in that section should be limited to a relatively restricted set of notes, typically 5 - 8 for tonal melodies.

"Centricity"
Prominence of a particular note throughout a piece or centeredness around such a note, ending there or serving as some sort of musical goal. This is usually the tonic for much of Western, tonal music.

Now, the beauty of this array of tools is their incredible flexibility as well as breadth of application. Many examples of tonal music do not exhibit one or more of these features, while conjunct melodic motion, limited macro harmony, and centricity can be found in virtually any piece of music.

We can also pick up any particular piece of music an examine it under the eye of a particular tonal feature.

* As termed by Dmitri Tymoczko in A Geometry of Music