Sometimes when we’re just booked to turn up and record live strings for a session, we are handed parts where all the notes seem to be in unison, (meaning all the instruments are playing the same note or are spaced octaves apart). Although the composer or band may have envisaged this sounding full and orchestral, it doesn’t really bring out the best qualities of a string section.
The spacing of chords is very important, and often string arrangements fall down because the notes of a chord are distributed either in the wrong inversion or with too large a gap between them.
Bearing in mind that the violins are in the same register, with the viola five notes below them and the ‘cello an octave below the viola, very often the upper strings can cover three notes of a chord with the ‘cello providing an anchor or counter melody underneath – generally making sure all three notes of the chord are there (or all four notes in the case of a 7th chord).
By using ‘double stops’ (using different strings to play more than one note simultaneously), this can help the chord to sound much fuller with the cello part never straying too far from the root of the chord.
Of course, context is everything – if we’re writing string parts for a solo voice with guitar, it’ll be composed in a totally different way than if we need to arrange a much more orchestral piece to accompany drums, guitar, brass and piano.