Html5 canvas game - loading different assets at different times instead of all at once

Hello everyone, I'll try to be brief.

I'm making an html5 game with Animate CC, and I must say I'm really glad with the final result. However, the preloader takes a lot of time - 'cause the game is somewhat big.

I was wondering if there's a way to avoid loading all assets (jpg files and sounds) at the beggining, and instead load each "scene" (or level) whenever you need it.

I was thinking of doing so by publishing multiple html-index projects, but how can I make them communicate? How can I load one of them at will?

I'll be very grateful if anyone can point me in the right direction,

thanks!