It's not simple! Have a look here:
Virtual Piano in C#[
^] - it uses a single WAV file which is programatically altered to change the frequency, which for music generation is probably a better "sound" than a "pure" tone.
The code is in C#, but it's pretty obvious, and online converters may help you convert it to VB for .NET
Though I'd strongly recommend you dump VB altogether, and switch to C#. VB6 is very, very different from "modern" VB and you will have a lot of VB6 habits which will not help you at all to produce "good" VB code. Switching to C# would "break the connection" to those bad habits, and hopefully make your long-term coding easier. An experienced coder should be able to pick up C# in between an afternoon and a week (depending on how experienced you are) - iutr;s teh .NET framework that takes the time to learn (and you need that for both "modern" VB and C# development).
There is a free book here:
https://www.robmiles.com/c-yellow-book[
^] which covers it well.