Short answers, pulled from the story.
Amir Khusrau created Hindustani classical music in the year 1253. He was a Persian-born musician who fused Indian melodic traditions with Islamic rhythmic complexities to establish a distinct sonic identity in northern India.
Vishnu Digambar Paluskar founded the Gandharva Mahavidyalaya in Lahore in 1901. This institution was one of the first to operate on public support and donations rather than royal patronage, allowing students from all backgrounds to learn the music.
Dhrupad was the main form of northern Indian classical music until two centuries ago and focused on devotional themes with long acyclic alaps. Khyal replaced Dhrupad as the modern Hindustani form of vocal music, shifting focus to emotional significance and improvisational capabilities.
The Hindustani classical music system uses seven basic notes with five interspersed half-notes, resulting in a 12-note scale. The relationship between these notes is fluid and context-dependent, unlike the fixed frequencies of Western music.
The sitar and sarod are the most popular string instruments, while the tabla is the most popular and versatile percussion instrument. The bansuri, sarangi, and harmonium also play important roles, with many instruments designed to emulate the human voice.