Thursday riddle poem #10

By Annette Marie Hyder

Sometimes your fingers kiss me lightly.

Sometimes they dance a tap.
They find their way all over me
by means of mnemonic map.
If you were the girl in Rumpelstiltskin’s tale
spinning straw to gold shiniest and rare,
the straw you’d spin would leap up and dart
to dance on electric air.
If you were a wordsmith dragon,
I’d be enough for an endless hoard.
I am the key to your vast vault.
I am a ________   ________.
What am I?
Take a guess.