Imagine a chess board, but seven-eighths wide

Question

My grandfather wrote me this riddle on a napkin when I was 12. It took me more than a year to solve, but I got it eventually. He said I didn't get it until I had explained the sections, so explain every line.

Imagine a chess board, but seven-eighths wide
and fit about five darker pieces inside.
I've got that, but seven times height,
I'm inch to yard black, and week to year white.

I've got flower-top feet, and a song in my heart,
And a nailhead's other half if you tear me apart.
I've a brother who smokes, you can tell from his pipes,
And some shady few others, the magnanimous types.

I'm not hung or high strung, though I'm still interstring,
I've an eighth of pale bees, without fear of stings,
No door stays locked to the tools in my hands,
So you should hear me sing from the farthest of lands.

What am I?

note: there are no typos in the riddle, I copied it just how I received it

Answer 1

You are

A piano

Imagine a chess board, but seven-eighths wide and fit about five darker pieces inside.

Picture a black and white pattern, with seven white an five black. Consider these as eighths due to the octave scale.

I've got that, but seven times height, I'm inch to yard black, and week to year white.

A piano has seven octaves with 36 black keys and 52 white keys.

I've got flower-top feet,

Pedals sound like petals

and a song in my heart,

A piano’s sound resonates from its central box.

And a nailhead's other half if you tear me apart.

Hammers strike the strings of the piano.

I've a brother who smokes, you can tell from his pipes

An organ, possibly a steam organ.

And some shady few others, the magnanimous types.

Other members of the keyboard family.

I'm not hung or high strung, though I'm still interstring,

The piano exists between the strings and percussion instrument families.

I've an eighth of pale bees, without fear of stings,

The B note is part of the octave, but does not have a sharp.

No door stays locked to the tools in my hands,

A piano has keys, but not in the locking sense.

So you should hear me sing from the farthest of lands.

Pianos are a worldwide distributed instrument