Because the voicings change quite a bit with what you're able to reach in different tunings.
I'm not saying alternate tunings are mandatory, just that you can't learn a single tuning with guitar and expect to only ever know just that. It's Very common to change tunings in guitar. Not so in Piano, that i've seen yet at least.
> Piano is also a stringed instrument, with one common tuning that most of us westerners play in.
Are there different tunings for Pianos? I'm not even sure what different tunings would look like, non-sequential pitch ordering? C next to G or something?
The only Piano "tuning" i'm familiar with is temperament, however that's functionally different than what we're talking about with Guitar.
Fair enough. I was just responding to your statement that guitar makes music theory more difficult. I'm not an expert in either instrument, and I think they each have their advantages and disadvantages. I like how scales and chord shapes (i.e. barre chords) are movable up and down the neck. It really taught me about transposing music and playing in different keys. On piano, a major triad chord looks different depending on the root note.
Today I was trying out the Sweet Child O' Mine intro and that's in a different tuning, although the shapes remain the same. (it's like capo -1). I know Drop D or other tunings can change the shapes for sure. However, for a casual guitarist, we can just concentrate on standard tuning and learn all the music theory that way.
For piano, I only know of Just Intonation and Equal Temperament, which still have the notes in the same orders. Although theoretically you could string and tune a piano differently....
I'm not saying alternate tunings are mandatory, just that you can't learn a single tuning with guitar and expect to only ever know just that. It's Very common to change tunings in guitar. Not so in Piano, that i've seen yet at least.
> Piano is also a stringed instrument, with one common tuning that most of us westerners play in.
Are there different tunings for Pianos? I'm not even sure what different tunings would look like, non-sequential pitch ordering? C next to G or something?
The only Piano "tuning" i'm familiar with is temperament, however that's functionally different than what we're talking about with Guitar.