I played with my graph paper this morning and worked out the measurements to make a keyboard. I wouldn't like to stitch anything narrower than 1/4" strip though.
The black keys were cut 1 1/2" wide x 4" long
The thicker ivory keys between the black were cut at 1 1/4" wide x 4" long
The thinner ivory strips were cut at 3/4" x 4" long
The whiter edge strips were cut 1 3/4" wide x 3" long

This is all including a 1/4" seam allowance.

I cut a small piece of ice-cream lid and used double sided tape on my machine to ensure a constant 1/4" seam - it worked!!! surprise surprise!!
I pressed the ivory seams towards the black. I pressed the ivory pair seams open. I was able to match the seams when I stitched the black/ivory strip to the ivory/ivory strip.
I'm so pleased - it worked the way I could see it in my head!!!

I had to share!

Looks good, be sure to show us the finished product

Looks good!

you are so clever. is this going on a musical theme quilt?

This is very neat! Can't wait to see the finished project.

This is to go under a printed music panel - I'm making a small wallhanging for my father's 80th birthday. He's a retired music teacher/band master/herald. I'll take a pic as I put it together...
I don't think it's too shabby....as I'm still a beginner!!! lol

Looks beautiful

You did a wonderful job with it. He will be impressed.

You did it! Good job.

You are so clever!! It almost looks playable!! Can't wait to see the whole thing finished!!

Ditter