Why do modern popular songs composed on piano sound different than songs composed on guitar?

Question

Songs that I hear that are piano based - ie. composed and originally performed on piano, seem to have a different feel than those composed on guitar. The flow, the movement, the chords used - are often very different for piano based songs vs. guitar based songs.

I don't mean which instrument they are played on. Any song can be played on either instrument. I am referring to which instrument was used by the composer, to compose or write the music. I am also not referring to a situation where someone takes a song, and composes an arrangement for one instrument or the other.

I find many songs written on piano, are more difficult to translate to an arrangement for guitar and maintain the same feel as the original played on piano. This is the source of my conclusion that there is something organically different between the two instruments as it applies to the way songs evolve from them.

I compose all of my original music on guitar because I am more proficient on that instrument. But I am wondering if I might get some interesting variations in my melodies and progressions if I started to compose some of my music on piano. And I wonder if some ideas or emotions that I want to convey lyrically, can be conveyed more effectively musically, on piano than on guitar.

What are some of the reasons that a song would manifest or evolve differently if composed on piano than if composed on guitar? And what type themes or ideas suggested by the lyrical content of a song (in the country, folk, pop, or rock genre') might be more effectively conveyed on piano than guitar?

EDIT: note addition of questions about how each instrument might better convey lyrical concepts musically.

Answer 1

Just a few ideas:

A keyboard instrument provides a lot more freedom in terms of the number of notes that can be sounded together and the distance between them. It's difficult on a guitar to play a fluidly moving bassline and a chord pattern two octaves above; it's trivial on a piano. The sustain mechanism of a piano allows for all notes to sustain at once; with a guitar, you have a maximum of six.

Some chord shapes are much harder on guitar than others - F barre is much tougher than open E, for example. There are some differences on the piano too, but it's much less of an influence on your chord and fingering choices. This can be seen be a disadvantage of the guitar, but can have interesting benefits in that more interesting chords can fall naturally under your fingers - instead of playing a full F barre, playing just F-C-F on the bottom three strings gives you some added notes on the three remaining open strings that you might not initially have chosen.

With a piano, the act of selecting the note to play and the act of playing it are the same thing; with guitar, you have a hand for each.

A piano gives far less flexibility in the ways you can play and mute notes, so the piano player will tend to add expression with arpeggiation and dynamics.

With a guitar, you can trivially slide a chord shape up and down, which you can't do on a piano. This is often done using one of the open strings as a pedal - of course it's possible to play a pedal on the piano too, but it doesn't encourage you to do so in the way a guitar open string does.

The musical traditions are somewhat different. There's more piano repertoire in the classical / common practice tradition, so you tend to get diatonic chord progressions with occasional modulations; Guitar chord progressions can be more rooted in folk and blues, so you get more modal scales, pentatonic scales, modal interchange... (massive over-simplification there and of course there is a huge body of work in all those traditions and more for both instruments, but it's still a consideration I think).

Answer 2

On the piano, your "reach" is sorted by pitch. On the guitar, it arranged "functionally" where notes one or several fourths (or third) apart are in close proximity.

So the guitar has certain chord voicings and shapes where you can put down your left hand and run a non-trivial picking pattern through the right hand, resulting in a fractured fill-in of the harmonic space. If you take, say, the picking pattern for Simon&Garfunkel's "Scarborough Fair", it is easy to play on guitar and would be a total mess on piano.

If you do arpeggios on piano, they can't be as out-of-order as a pattern on the guitar.

Now the piano is great at stacking thirds and seconds, which are smaller intervals than the "default" guitar interval from one string to the next. So piano chord culture leans towards accumulating denser populated non-orthodox chords than the guitar prefers. Also guitar tends to focus on getting the bass note accurate and not be all that picky about the chord shape stacked on top: that's more or less determined by where fingers go nicest and if some notes are missing or double, that's not a cause for worry.

Chord inversions are pinned downed harder on piano: you don't just start a right-hand arpeggio anywhere you want and end it when convenient. The sustain of the piano is also more aggressive: if you have some half-melodic/half-harmonic picking on the guitar, chances are if you pedal it on the piano, you get something mushy rather than charming.

It is interesting to play the fugues from the Bach violin solo sonatas on both guitar (to which they map astonishingly well) and piano. Actually, I don't really have the comparison with piano but played it on chromatic button accordion (a polyphonic keyboard instrument) which stacks minor thirds horizontally where the guitar stacks fourths, and consequently allows playing stuff spread apart further than on the piano (even people with small hands can reach two octaves on a CBA). So I'm not sure about the playability on piano.

At any rate, the character of those spread-apart voicings (the violin is even tuned in fifths rather than the guitar's fourths) results in a totally different harmonic framework than the usual tight harmonic voicings in piano music. It's the art of painting harmonies by omission.

That's done a lot on the guitar, and not all that much on piano.

Answer 3

I don't mean which instrument they are played on

I think the instrument is a big part of it. Pianos can play way more notes at a time. Stomp the hold pedal and you can play a lot more strings than a guitar player can. The piano has a full 88 notes of range. It takes 2 or 3 guitars to cover A0 .. C8. The guitar lets you bend notes, and fiddle with the sound in the middle of playing a note. The piano doesn't (synth keyboards do to some extent).

Those are very significant differences that have a direct affect on how you'll arrange your song.

Answer 4

I'm painting with a broad brush here, but I think that keyboard and guitar players do tend to think differently about how a tune is created.

One way to write a tune is to start with a chord progression and a rhythmic feel, and then weave a melody over the top. Sometimes the melody is more rhythmic than melodic with repeating notes of the same pitch. Whilst the melody 'fits' the chords, it might not be bound to them ever so tightly. I've noticed certain out-of-chord notes such as the sixth are often heavily emphasised (especially on the V chord for some reason), even though the chord isn't an add6 chord. The chords tend to be regularly spaced, e.g. one or two per bar.

An alternative way is to begin with a melody, and then harmonise it, changing chord as the melody takes it. There might well be sequences of rapid chord changes where the melody moves rapidly. Technically some of these might be passing-chords. (Classical four-part harmony could be seen as an extreme example of this.) Generally the melody is tightly coupled to the chord changes, and out-of-chord notes are usually specifically to create tension that is then released with a resolution.

My observation is that guitar players seem to favour the former method and keyboard players the latter. This is probably because if the guitarist is singing the melody then it is naturally decoupled from the chords. Whereas if you are playing the melody and harmony together they tend to couple naturally. In addition, rapid chord changes are easy on the piano but not so much on the guitar (except when shifting barre chords one or two frets at a time).

Answer 5

There are two elements I think.

The FIRST thing a guitarist lears is how to strum a chord. His thinking is chord-based. A keyboard player's first exercise is to play a simple TUNE.

And, of course, different patterns lie 'under the fingers' on guitar and keyboard.

There's another category - pop songs composed on a sequencer. Characterised by incessantly repeated pattens, a 'layering' approach to orchestration and often lyrics rhythmically chanted rather than sung.