Gharanas exist even in kathak. It was only later that the term acquired wider meaning, coming to include disciples, grand-disciples and so on, from outside the family. Gharanas were identified by the name of the city, town or village that the founder of a specific musical style hailed from.
In the past, gharanas were better defined in terms of differences in repertoire, technique and stylistic features. But there were instances of some musicians adopting an eclectic musical approach, with the result that they studied under more than one guru, many of whom belonged to different gharanas.
This eclectic flavour has increased over several decades, with modern media providing greater access to several musical styles. Gharanas in vocal music seem to have still retained some of their original traits, but this is less evident in instrumental music. In the latter case, the styles are now often identified by the name of one or another path-breaker.
Gharanas of sarod players have their origins in the lineages of the Pathan communities that brought the Afghan rabab to India. They studied Hindustani art music under descendants of Miyan Tansen, the court musician of Emperor Akbar, and were responsible for giving shape to the sarod. Further changes in the instrument were introduced by respected sarod player and guru Allauddin Khan and his brother Ayet Ali Khan.
Fortunately, we have recordings of the early sarod styles. Eminent sarod player Hafiz Al Khan, a descendant of one of the original Bangash families that migrated to India, narrates anecdotes related to his training and performance career in this short interview, which ends with an aalaap played by his son, the well-known performer Amjad Ali Khan.
The Maihar-Seniya gharana founded by Allauddin Khan has among its exponents his son and disciple Ali Akbar Khan, who has been revered by musicians for his profound artistry. Allauddin Khan also trained several other noteworthy disciples, not all of whom were sarod players. Internationally-acclaimed sitar maestro Ravi Shankar was one of his foremost disciples. Here is a Films Division documentary on Allauddin Khan.
Among the short films on music made by JBH Wadia Movietone is this recording of a sarod recital by Sakhavat Hussein Khan of the Lucknow-Shahjahanpur gharana.
Radhika Mohan Moitra, a sarod player from a Bengali aristocratic family, belonged to the Shahjahanpur gharana of Mohammad Amir Khan. Here’s an audio clip featuring him: