Play a duet with a piano that “responds to you”.
Audacity is an open-source (free download), sound editing program that will give you a lot of options for sound editing.
Chrome Music Lab
Cross-platform experiments with musical concepts including; Song Maker, Rhythm, Chords and arpeggios.
Create “grooves” using math concepts.
How to Soundproof a Cardboard Box
There are several different methods for soundproofing for high quality audio production. This is one option.
Free Music Archive
Royalty free music files.
Royalty free audio clips. Great for adding ambiance to your podcast.
Semi-conductor allows you to conduct an orchestra in a browser, by moving your arms.
NPRs curriculum for educators on teaching podcasting.
Adobe Spark includes a free option and can be used to create video stories (and web pages and graphics).
How to Create a DIY Green Screen Video Effect
Information on creating the screen, taking video and editing.