The key features of a 'pop' singing style
Singing the words as closely to speech as possible. So not the lengthened vowels and clipped consonants of classical singing. And sing the words as if you mean them. Emotion and communication are key. Often this means singing in your 'speech quality' voice rather than your upper register.
Pop inflections aren't an add-on. They're there to aid the expression of the song. Ditto dynamics and taking breaths: sometimes we take a breath in a pop song not because we've run out of breath, but because it's the right moment for the song.
Only use 'vibrato' if it's appropriate.
Be very aware of pronouncing the words in a fake American accent in order to sound more poppy. This rarely works. Sing in your own accent.
Stevie Wonder... He pours passion and emotion into every line. When he sings Isn't she lovely, you know he's got a massive smile. Really important for any singer to listen to a singer like him and realise how much you can communicate.
This guide to singing 'pop' is part of our 'Create singing stars' guide.