Mitchell Kristopher Rowland is an American songwriter and multi-instrumentalist, best known for his work as a touring guitarist and for co-writing songs on all three of Harry Styles's solo albums. "Watermelon Sugar", a song he co-wrote with Styles, Tyler Johnson, and Thomas Hull, was nominated for and won Best Pop Solo Performance at the 63rd Annual Grammy Awards in 2021. Rowland, along with Styles, Johnson, and Hull, also won the Brit Award for Song of the Year for "Watermelon Sugar" at the 2021 Brit Awards. Description above from the Wikipedia article Mitch Rowland, licensed under CC-BY-SA, full list of contributors on Wikipedia.