如何在flutter中播放背景中的整个音调

import 'package:flutter/material.dart';
import 'package:flutter_sound/flutter_sound.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Flutter Sound Demo'),
        ),
        body: Center(
          child: ElevatedButton(
            child: Text('Play Sound'),
            onPressed: () {
              playSound();
            },
          ),
        ),
      ),
    );
  }

  void playSound() async {
    FlutterSound flutterSound = FlutterSound();
    await flutterSound.startPlayer('path_to_audio_file');
    flutterSound.setPitch(1.0); // 调整音调
    await flutterSound.stopPlayer();
    flutterSound.release();
  }
}