Task: I want to save Luciano Pavarotti songs in the playlist so that i will listen to my favorite songs in future without searching one by one. Create a playlist name with Luciano Pavarotti and add It's A Man's Man's Man's World (Stereo) song in the YouTube app
Steps:
Open the YouTube app
Swipe down the current pause video
Click on the Library tab at the bottom right of the screen
Click on the Create new playlist button
Click on the It's A Man's Man's Man's World (Stereo) song 
Click on the Next button at the top right of the screen
Click on the Title text field
Type Luciano Pavarotti
Click on the Create at the pop up window