In most worship songs, it is pretty obvious when the song is a “piano song” or a “guitar song.” When a song is a piano song, it may have more chord changes (think hymns), and the groove generally derives from the chord structure. Conversely, when a song is a guitar song it may have less chord changes, and the groove derives from the rhythm of the instrument or some lick or hook. This is something you are probably intuitively aware of and consider when arranging the song, but let’s focus on it directly for a moment and consider some implications.
A few years back (maybe before the internet even!) I remember reading a huge interview in Keyboard magazine with Michael Tilson Thomas* in which he talked about composition separate from that of any given instrument. In other words, he didn’t want the physicality of writing at the piano to suggest certain things in the composition. Rather, he wanted to compose independent of any instrument and then later on figure out how to voice it.
Being aware of this dynamic, there is one obvious idea and one less obvious idea we can learn:
The obvious idea is a neat arranging trick. If you have a piano song and you want a fresh arrangement, you can really change it up by arranging it around the guitar. Conversely, if you have a guitar song and you want a fresh arrangement, you can really change it up by arranging it around the piano. This is most famously done by taking hymns generally written at the piano, and making guitar arrangements. An example in the other direction – I was asked to arrange a piano version of one of Chris Joyner’s tunes for a song he wrote on the guitar called “I Believe“.
A less obvious idea is that there is a very real sense that the physicality of our instrument dictates a lot of how we play it. So while we should to play to our instrument’s strengths, we should avoid being limited by that (due to lack of technical skills), or held in a box by that (due to a lack of imagination).
So the former is probably easy enough to understand; we should try to minimize limitations by our technical skills. But the latter is a blind spot. For example, how often do we play monophonic (let alone with just one hand) on the piano? If a simple melody or counter-melody best serves the song, we should play just that (rather than chords) as suggested by our many fingers and all those keys.
Instruments are means to an end. The end is the song. How best can we voice the song?
*famed conductor of San Francisco Orchestra and notable re-interpreter of classic American composers such as Aaron Copland.