Complex sentence: Under a shady cool tree, Guru Nanak and Bhai Mardana started reciting Kirtan, the devotees gathered together which annoyed Wali Qandhari but he was helpless.
Split into simpler sentences: Under a shady cool tree, Guru Nanak and Bhai Mardana started reciting Kirtan and their devotees gathered around. This annoyed Wali Qandhari but he was helpless.