Here are all the files that are used for the projects.
They are free to use and download, but please mention where you got them from if you use them in your projects.

Piano sprite files can be found here: Piano
Scratch code for piano: Piano scratch

Files for Scratch programming series

These files can be used either on Scratch's website, or with the Scratch app.
To use them on https://scratch.mit.edu/ you need first to download the sb3-file from here, then do the following:
1. Press 'Create' on their website
2. Press 'File' and then 'Load from your computer'
3. Choose the file you downloaded from here.

Scratch Academy

Episode 1 - Basic:
Scratch code Example 1
Scratch code Example 2

Episode 2 - Movement by keys: Example

Episode 3 - Movement by mouse: Example

Episode 4 - Sideways scrolling: Example

Episode 5 - Upwards scrolling: Example

Episode 6 - Backgrounds: Example

Episode 7 - Colliding objects: Example

Episode 8 - Math: Example

Episode 9 - Clones: Example

Episode 10 - Easy gravity: Example

Episode 11 - Random numbers: Example

Episode 12 - Lists: Example

Scratch University

Episode 1 - Maze: Example