Gradient transparency in clipping mask?

Hello!

I have a graphic that I need to recreate. It's sound waves with a colored gradient from left to right (attached).

In my mind, I was going to do this by first creating a line shape with gradient fill, black with slight transparency on the top and bottom of each line, duplicate and resize, group that, put it over a rectangle with a gradient using the colors in the image I attached, create clipping mask.

Clipping mask gets rid of transparency so that doesn't work. It's just solid. I need that feathering at the ends of those lines.

Do it manually using the eye dropper to pick the colors and copy/paste a few dozen times?

Any tips from you masters of Illustrator are very much appreciated.

Thanks!