Spreading your voices is very important! It creates more balanced sounding voicings. Rather than having the notes in your voicing all close together (as in a triad), try to use a larger range of the piano.
Let’s take the beginning of ‘Amazing Grace’. The melody is a G, with a G major chord. We could just play it as a triad in our left hand:
As you can see, there’s a large gap between the melody and the the chord. If you play it, you’ll hear that it sounds unbalanced. The chord is very low, and dark sounding, and the melody is far removed from it. A better of playing it would be to move the third of the chord (B) up an octave, played in your right hand thumb:
In this version, the voices are evenly spread out. The intervals between them are roughly equal. When you play this on the piano, you can hear how much more balanced it sounds.
Spreading voices often means moving notes up an octave and then playing those voices in your right hand, underneath the melody. This poses an additional challenge to play, but it makes for much better sounding chords.
