Singer, composer, manager and producer. Co-founder of the Please the Trees band, he is the author of their lyrics and music as well as manager and booking agent. Since 2011 Please the Trees plants a tree in every city where they play. He co-wrote music to a Radim Špaček movie, Places, together with English musician David Boulter. As a producer and manager, Havelka works with music and film festivals such as Colours Of Ostrava, United Islands Of Prague, Metronome Prague a Letní filmová škola v Uherském Hradišti. He performs with his eight years old son, Šimon, who plays drums, as Sun+Dead. As a member of independent booking agency Scrape Sound Inc. Havelka co-organised dozens of concerts of mainly foreign artists.