I finished to create Hello world and now i want to create some atleast app.so how can i start?

[Justech]

I want to make some music app.but how can i do it ??

  #include <iostream>
using namespace std;
int main ()
{
cout <<"Hello world";
}

[Moschops]

Decide what the program is meant to do with this "music" of which you speak.
Decide on your target hardware and OS.
Get appropriate libraries.
Learn to use the libraries.
Write code.