We had the following problem:

We need a Slideshow/PowerPoint Presentation for Song-Lyrics and Normal Text inbetween

Now you could do that all by hand (which I did for long enough). But due to the fact that most of the stuff is the same in every Slideshow (Song lyrics don't change that much), you can basically create an agenda and have the rest generated for you. That is the Idea and main feature of this Slideshow Generator (check the Github Repo for the Code). You pass in a yaml file containing the agenda of the songs (or other prebuilt slides) and the custom text for the rest of the slides, and voila you have a complete Presentation. The Project is a bit dated, so it might not work right outside the box, but with a bit of library updating and tweaking you should be up and running in no time (at least i hope so). This uses some python to generate all the files, but the heavy lifting is done by RevealMD, which is built on RevealJS.