need a specific type of program that...

[thechinesehero]

lets you create your own beats.. any thing like that ?

 

[farmercal]

Acid Music

 

[junkerman123]

fruity loops studio

 

[konichiwa]

fruity looooops

 

[nakedfrog]

In addition to the above:
Rebirth

 

[djpolstee]

Reason is fun