It’s been very interesting to see the difference in music appreciation between Siena and Thalia. From what we remember of Siena around Thalia’s age and what we’ve observed in Thalia, Thalia appears to want to bang on the keys of the synthesizer more than Siena did. She also responds better to singing; certain songes almost always makes her happy and clap her hands.
That being said, Siena is a pretty fierce drummer. Sure she can bang keys on the piano too, and she can actually sing decently (as evidenced by the Donut Song), but she is probably best at banging a drumstick on some surface. Drums not technically required.
My thinking, therefore, is that even if Siena is not the best singer, keyboardist, or drummer in the world, or even necessarily pro-grade, if we nurture enough of it and she gets the right looks, for which she’s well on the way, then all she will need is to be fronted by a really stellar songwriter/guitarist/singer. So, basically, she needs to be Meg White.