What is "khyal"

Khyal (or Khayal, Urdu: خیال, Hindi: ख़्याल, ) is the modern genre of classical singing in North India. Its name comes from an Arabic word meaning "imagination". It appeared more recently than dhrupad, is a more free and flexible form, and it provides greater scope for improvisation. Like all Indian classical music, khyal is modal, with a single melodic line and no harmonic parts. The modes are called raga, and each raga is a complicated framework of melodic rules.