Step 1:
Open a new Blank Powerpoint Presentation.
Insert all the song lyrics into the slides.

Step 2:
Click Insert > Sound from File
Select a suitable MP3 song to put in.

How do you want the sound to start in the slide show?
Choose Automatically.
Once your your MP3 sound is set up, select Effect Options to set how you would like to play the sound.

Under the Effect tab, make sure you key in the number of slides when you would like to Stop playing.

Step 3:
Click to select the text frame.

At the top of the office bar.
Click Animations > Custom Animation.
There you can Add Effect for your lyrics.

Click on Emphasis, then choose Color Wave.

Modify the Color Wave, follow the settings below:
Start: With Previous
Speed: Fast

For Speed, you can adjust to suit your song.
Adjust your Timing so that the lyrics can run according to song.

Step 4:
Set your slide transition Automatically After the time you want and key in the transition period.

After all, preview your Karaoke Slides Show by pressing the F5 key on your keyboard, it will play according to the song.

Some important notices:

Make sure you included your MP3 file in the same folder.

Turn off all active running programs during the automatic timing Slides Show to avoid any pop-up to disturb your slide show.