The first was created to showcase the features of Ultra High Performance Concrete by German engineer Ricardo Kocadag and actually sounds pretty good. You can hear it on this Facebook video. Read more about it here.
The second you can hear below and was made by Kulish Design Company for the 2015 World of Concrete exhibition.
I don't see concrete catching on as a storage medium any time soon, but it does show the technology isn't limited to plastic.