Time for a riddle

Question

Here's a riddle. It's my first on here so hopefully it's not too easy. Since you can't really solve a riddle you came up with, it's difficult to judge how hard they are.

My stem's planted firmly where I am allotted.
My tail is wavy and my face is quite blotted.
I relay much emotion though flatly I'm spotted,
And I grow half my size whenever I'm dotted.
I can speak any language, yet utter no words.
I'm no seed, yet I am well known among birds.

But I do have a speech impediment:
I can say cage but not page, aged but not wage.
I can say deaf but not red, bed but not sled.

I live on a highway that's structurally sound,
Where you might see my friends accidentally bound.
It has many lanes, and also long lines.
There are lots of sharp turns, but plenty of signs.

I am played but not won, made but not spun.
The key is to measure before you've begun.

What am I?

Answer 1

You are:

Music

My stem's planted firmly where I am allotted.
My tail is wavy and my face is quite blotted.
I relay much emotion though flatly I'm spotted,
And I grow half my size whenever I'm dotted.

This describes an eighth note - a stem, a wavy tail, a filled-in face;
the half-again growth when dotted is what gave it away to me.

I can speak any language, yet utter no words.
I'm no seed, yet I am well known among birds.

Music has no words of its own, but can be used to express feelings to anyone of any language. And, of course, song-birds sing musically.

But I do have a speech impediment:
I can say cage but not page, aged but not wage.
I can say deaf but not red, bed but not sled.

The notes of music only run A-G, so the indicated words can either be spelled with those letters (cage, aged, deaf, bed) or not (the rest).

I live on a highway that's structurally sound,
Where you might see my friends accidentally bound.
It has many lanes, and also long lines.

These lines describe the staves of musical notation

There are lots of sharp turns, but plenty of signs.

Sharp notes, rests, and so on are other items of musical notation.

I am played but not won, made but not spun.
The key is to measure before you've begun.

Music is played and made, but not won or spun.
"Key" and "measure" are additional musical terms for things usually signalled at the start of a piece (well, of a staff line anyway) in the sharps or flats and with the time signature.

Answer 2

I haven't worked out all the clues, but I suspect you're

a piece of paper with writing on it.

My stem's planted firmly where I am allotted.

The "stem" being a pen or pencil used to write with?

My tail is wavy and my face is quite blotted.

Not sure what the "tail" is (perhaps writing tailing off in a curve?), but the "face", the sheet of paper, would be blotted with ink after having been written on.

I relay much emotion though flatly I'm spotted,

Written words can relay much emotion, even though they're just dots of ink on a flat surface.

And I grow half my size whenever I'm dotted.

Not quite sure about this - something to do with dotting the i's and crossing the t's maybe?

I can speak any language, yet utter no words.

Definitely.

I'm no seed, yet I am well known among birds.

Birds using paper to line their nests?

But I do have a speech impediment:
I can say cage but not page, aged but not wage.
I can say deaf but not red, bed but not sled.

I'm not really sure about this verse. Presumably it's something to do with how those words are written down.

I live on a highway that's structurally sound,

A pad or ream of paper.

Where you might see my friends accidentally bound.

A book consists of sheets of paper "bound" together.

It has many lanes, and also long lines.

Lined or ruled paper with margins.

There are lots of sharp turns, but plenty of signs.

Written signs on the paper, and right angles at the corners?

I am played but not won, made but not spun.
The key is to measure before you've begun.

I'm not quite sure about this verse either.