🔐 The first clue

I have black and white keys,
yet I open no doors.
Together with my strings,
I create music.

 

What instrument am I?

Only open a hint if you really need it

A nudge

A = 1  Z = 26

 

The numbers you need are:

16 – 9 – 1 – 14 – 15

 

Turn them into letters, and this instrument will allow you to begin.