Apps Various java implementation question

[Yen Yu]

Hi guys,

I'm currently implementing on an android apps for my final year project which helps on current parents on saving some good money and time with this E-Tutor for toddler. Currently I've created a subpage which navigates from Mainpage-> Music page. At which the Music page allows to play some music after hitting various music button, and also having a "Back to Home" button.

First question: - How am I able to implement efficiently that different button tagging to various individual songs instead of creating 8 different classes for 8 different buttons tagging to each song individually? Below is my short codes.
=====MusicActivity Class==========================
button = (Button) findViewById(R.id.btnButton16);
button.setOnClickListener(new OnClickListener()
{
@override
public void onClick(View v)
{
BtnButton16.play(getBaseContext(), R.raw.test);
}
});
}
==============================================

=====BtnButton16 Class==========================
import android.media.MediaPlayer;
import android.content.Context;
public class BtnButton16 {
private static MediaPlayer mp = null;
//private static MediaPlayer mpEffect = null;
public static void play(Context context, int resources)
{
mp = MediaPlayer.create(context, resources);
mp.start();
}
public static void stop(Context context)
{
if (mp != null)
{
mp.stop();
mp.release();
mp = null;
}
}
}
==============================================

Second question: - How am I able to prevent music from playing again(stack or overlapping songs) after hitting the same "Song" button or other button?

Third question: - How am i able to stop music immediately after i hit the "Back to Home" button? It seems like if I implement mp.stop(); command within my "Back to Home" button, it will create error which force the program to close off.
=====BtnButton23 (Back to home)======================
button = (Button) findViewById(R.id.btnButton23);
button.setOnClickListener(new OnClickListener()
{
@override
public void onClick(View arg0)
{
//mp.stop();
Intent intent = new Intent(context, MainContent.class);
startActivity(intent);
}
});
================================================

Need some professional help! Thanks all in advance of assisting and enlightening me on my project work.