When they're in the booth, vocalists are being asked to make words sound different to compliment the music and sounds. The results can be very effective, however there are also a large number of misunderstood songs: you've only got to read this article to realise just how widespread this has become in popular music.
Diction is something I like to work on throughout tuition with my students. Less about the old fashioned 'lips, teeth, tip of the tongue', more picking an interesting and wordy song to run with as an exercise.
Below are three of my current suggestions; feel free to add to this with your choices:
1. Wild Things, Alessia Cara One of my current favourites, this song is lyrically rich, along with a great, jazz inflicted melody.
2. The A Team, Ed Sheeran Famed for his story telling, Sheeran's songs will never leave you short of a lyric to sing and a story to tell.
3. One Week, The Bare Naked Ladies If you can wrap your teeth around the Chinese chicken bit and still be understood then you've got it!