I love this:

A South Indian legend records that Tumburu once performed severe austerities and pleased Shiva. Tumburu asked Shiva to grant him a horse-face, immortality, liberty to travel the universe, skill in music and singing, and the ability to reside with and serve Shiva. Shiva blessed him and granted the boons that he sought.[5]

I feel like I need to find out why he wanted to have a horse face?

Perplexity put together a not bad reply to this, citing sources that I haven’t checked, and probably won’t:

According to Indian mythology, Tumburu asked Shiva for a horse face for the following reasons:

  1. As a result of severe austerities: Tumburu performed intense penance to please Lord Shiva. After successfully gaining Shiva’s favor through his devotion and austerities, Tumburu was granted the opportunity to ask for boons.
  2. To obtain a unique appearance: By requesting a horse face, Tumburu sought to distinguish himself with a distinctive and memorable appearance. This unusual feature would set him apart from other celestial beings and musicians.
  3. To gain special powers: In some interpretations, the horse face may have been believed to grant Tumburu enhanced musical abilities or other mystical powers associated with his role as a divine musician.
  4. As a sign of devotion: Asking for such an unusual boon could be seen as a demonstration of Tumburu’s complete surrender and devotion to Lord Shiva, showing that he valued Shiva’s blessing over conventional beauty.
  5. For immortality: Along with the horse face, Tumburu also asked Shiva to grant him immortality. The horse face may have been seen as a small price to pay for the gift of eternal life.

It’s worth noting that while the horse face is a defining characteristic of Tumburu in many accounts, the exact reasoning behind this specific request is not always explicitly stated in the mythological texts. The horse face has become an integral part of Tumburu’s iconography, often depicted in Indian visual art and described in various legends related to this celestial musician.

Reading that with my mythical goggles on, the part about demonstrating complete devotion makes a lot of sense, if you think of Tumburu offering himself basically to be the mount of Shiva, and to be driven by Shiva’s will for all eternity, etc. “Cool story, bro.”