//necessary import declarations go here
public class Settings extends PreferenceActivity implements OnSharedPreferenceChangeListener{
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);
        SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(this);
        app_preferences.registerOnSharedPreferenceChangeListener(this);
    }

    public void  onSharedPreferenceChanged  (SharedPreferences  sharedPreferences, String  key)   {
        Log.d("onSharedPreferencesChanged", "sharedPreferences changed.  key: " + key);
        Editor preferencesMod = sharedPreferences.edit();
        String instrumentChoice = sharedPreferences.getString("instrumentList", "Guitar");
        if(key.equals("instrumentList")) {
            Log.d("Settings", "key is instrumentList.  chooseTuning before if: " +    sharedPreferences.getString("chooseTuning", "no luck"));
            if(instrumentChoice.equals("Guitar")) {
                preferencesMod.putString("chooseTuning", "Standard");
                preferencesMod.commit();
                Log.d("Settings", "chooseTuning after if: " +      sharedPreferences.getString("chooseTuning", "ciao"));
            }
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
        android:title="Settings">
  <ListPreference android:title="Choose an Instrument" android:key="instrumentList" android:entryValues="@array/instruments" android:entries="@array/instruments"/>
        <ListPreference android:title="Choose Tuning" android:key="chooseTuning" android:entryValues="@array/tuningChoices" android:entries="@array/tuningChoices" android:persistent="true"/>
</PreferenceScreen>

ListPreference list = (ListPreference) getPreferenceManager().findPreference("myList");
    list.setValue(sharedPrefs.getString("myList", "default"));
    list.setOnPreferenceChangeListener(new OnPreferenceChangeListener() {

        public boolean onPreferenceChange(Preference preference, Object newValue) {
            sharedPrefs.put("myList", newValue.toString());
            return true;
        }

    });

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(this);

    boolean loadDefaults = app_preferences.getBoolean(DEFAULTS_LOADED, true);
    if(loadDefaults)
    {
        addPreferencesFromResource(R.xml.preferences);
        Editor editor = app_preferences.edit();
        editor.putBoolean(DEFAULTS_LOADED, true);
        editor.commit();
    }
    app_preferences.registerOnSharedPreferenceChangeListener(this);
}

ListView list = preferenceActivity.getListView();
list.performItemClick(list, 1, list.getItemIdAtPosition(1));

PackageInfo packageInfo = null;
                try {
                    packageInfo = preference.getContext().getPackageManager().getPackageInfo(preference.getContext().getPackageName(), 0);
                } catch (PackageManager.NameNotFoundException e) {
                    e.printStackTrace();
                }
                preference.setSummary(packageInfo.versionName);