The Combination of Harmony and Counterpoint (cont.)
A consonant skip contains only notes from the harmonic unit that it is prolonging (in the case of C major, only C, E or G). It may leap from one note of the harmonic unit to any other - it is, in other words, an incomplete arpeggiation.
In a Schenkerian analysis diminutions generally prolong both a harmonic unit and a particular note from this unit. As in an arpeggiation, both notes in a consonant skip are taken from the triad of the harmonic unit, so only context could tell us which note is the one being prolonged.
Note the way that Schenkerian analyses are notated: there are no stems on the noteheads and a slur spans the linear unit or diminution in question. Stems, beams and minim noteheads are used at other stages of an analysis (see Notation Guide)