Vibration motors

so i'm developing a product which is essentially a mini piano. i want to be able to program sheet music into the arduino and for it to show up on an lcd screen. i would like each note to be spoken as it possibly lights up and each according key to vibrate with this. i was hoping that the speed of the song could be increased and decreased which would also allow the vibrations to increase or decrease in speed. do i need an actual device or buton to make his happen or will i just change the code to increase or decrease the vibration speed? any help at all would be greatly appreciated as i'm a complete beginner and don't even know where to start! thank you

You can achieve it in code.
Look at PWM (pulse width modulation).
What it does is, it rapidly turns on an off your motor very quickly to achieve different motor speeds.

How many keys will your piano have?
If you run out of PWM pins on Arduino you can use software PWM libraries of shift registers PWM libraries to get more.

great thank you very much for your response. the device will only be used as a training device to help people learn how to play the piano so it will only have 8 keys. i was hoping to try and program one song onto the arduino so the corresponding keys will vibrate as each note plays. will i need one PWM pin for each vibration motor, or will one work with all 8?

Well, you could conceivably do it either way, but it would be simpler to have one PWM pin for each motor.

okay sounds great, i'll give that a try. thank you!