Complex sentence: Declan Benedict McKenna (born 24 December 1998) is an English singer, songwriter, and musician best known for winning the Glastonbury Festival's Emerging Talent Competition in 2015.
Split into simpler sentences: Declan Benedict McKenna (born 24 December 1998) is an English singer, songwriter, and musician. He gained recognition for winning the Glastonbury Festival's Emerging Talent Competition in 2015.