Is it possible to have music playing while browsing through the app?
Yes it is possible
Try the Player component
A very good way to learn App Inventor or Kodular is to read the free Inventor’s Manual here in the AI2 free online eBook App Inventor 2 Book: Create Your Own Android Apps … the links are at the bottom of the Web page. The book ‘teaches’ users how to program with AI2 blocks.
There is a free programming course here Course In A Box and the aia files for the projects in the book are here: App Inventor 2 Book: Create Your Own Android Apps
How to do a lot of basic things with App Inventor are described here: How do you...? .
Also do the tutorials Our Tutorials! to learn the basics of App Inventor, then try something and follow the [Top 5 Tips: How to learn App Inventor](App Inventor: How to Learn | Pura Vida Apps
Taifun
Do you mean to play audio while in other screens?