NSString *mp3one=[[NSBundle mainBundle] pathForResource:@"1" ofType:@"mp3"];
NSString *mp3two=[[NSBundle mainBundle] pathForResource:@"2" ofType:@"mp3"];
NSData *oneData = [[NSData alloc]initWithContentsOfFile:mp3one];
NSData *twoData = [[NSData alloc]initWithContentsOfFile:mp3two];
NSMutableData *data = [[NSMutableData alloc]init];
[data appenddata:oneData];
[data appenddata:twoData];

self.player = [[AVAudioPlayer alloc]initWithdata:data error:nil]; [self.player play];