play_song（）里有死循环while(1)，程序到这里打转转了。

给你一个蜂鸣器音乐与流水灯同时实现功能的编程思路，不代表此程序能够直接正常运行。
#include "reg52.h"

sbit buzzer=P2^3 ;                        //蜂鸣器控制脚　

unsigned char code SONG1[]={//音乐频率数组，
0x26,0x20,0x20,0x20,0x20,0x20,0x26,0x10,0x20,0x10,0x20,0x80,0x26,0x20,0x30,0x20,
0x30,0x20,0x39,0x10,0x30,0x10,0x30,0x80,0x26,0x20,0x20,0x20,0x20,0x20,0x1c,0x20,
0x20,0x80,0x2b,0x20,0x26,0x20,0x20,0x20,0x2b,0x10,0x26,0x10,0x2b,0x80,0x26,0x20,
0x30,0x20,0x30,0x20,0x39,0x10,0x26,0x10,0x26,0x60,0x40,0x10,0x39,0x10,0x26,0x20,
0x30,0x20,0x30,0x20,0x39,0x10,0x26,0x10,0x26,0x80,0x26,0x20,0x2b,0x10,0x2b,0x10,
0x2b,0x20,0x30,0x10,0x39,0x10,0x26,0x10,0x2b,0x10,0x2b,0x20,0x2b,0x40,0x40,0x20,
0x20,0x10,0x20,0x10,0x2b,0x10,0x26,0x30,0x30,0x80,0x18,0x20,0x18,0x20,0x26,0x20,
0x20,0x20,0x20,0x40,0x26,0x20,0x2b,0x20,0x30,0x20,0x30,0x20,0x1c,0x20,0x20,0x20,
0x20,0x80,0x1c,0x20,0x1c,0x20,0x1c,0x20,0x30,0x20,0x30,0x60,0x39,0x10,0x30,0x10,
0x20,0x20,0x2b,0x10,0x26,0x10,0x2b,0x10,0x26,0x10,0x26,0x10,0x2b,0x10,0x2b,0x80,
0x18,0x20,0x18,0x20,0x26,0x20,0x20,0x20,0x20,0x60,0x26,0x10,0x2b,0x20,0x30,0x20,
0x30,0x20,0x1c,0x20,0x20,0x20,0x20,0x80,0x26,0x20,0x30,0x10,0x30,0x10,0x30,0x20,
0x39,0x20,0x26,0x10,0x2b,0x10,0x2b,0x20,0x2b,0x40,0x40,0x10,0x40,0x10,0x20,0x10,
0x20,0x10,0x2b,0x10,0x26,0x30,0x30,0x80,0x00};
unsigned char code SONG2[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};//流水灯数组

unsigned char Count;
unsigned int i;
unsigned char j;

void Time0_Init()
{
        TMOD = 0x21;
        TH0  = 0x3C;//50ms
        TL0  = 0xB0;//50ms
        TH1  = 0x00;
        TL1  = 0x00;
        TR0  = 1;
        TR1  = 1;
        EA          = 1;
        ET0  = 1;
        ET1  = 1;
}

void Time0_Int() interrupt 1
{
    TH0  = 0x3C;
    TL0  = 0xB0;
        Count++;
        if(Count%5==0)//250ms节拍
        {
                i++;
                if(i=='\0')
                        i=0;
                TH1=SONG1[i];//T1重装值，音乐频率
        }
        if(Count==10)//500ms流水灯变化速度
        {
                Count=0;
                j++;
                if(j=='\0')
                        j=0;
                P0=SONG2[j];//流水灯花样
        }
}

void Timer1Int() interrupt 3
{
        buzzer=~buzzer;       
}

void main()
{
        Time0_Init();
        while(1);
}

函数play_song（）包含while（1）语句。 将“ 1”更改为适当的条件。

不太明白你的描述，心形灯会亮吗？你的程序写的就是先播放曲子然后亮灯，所以是不可能同时动作的，想要曲子和灯一起，就不能顺序写下来

因为程序是一步一步执行，从主程序看，找执行播放音乐函数，播放完音乐再去执行流水灯的程序，这两个程序是排着队串行处理的，要想并行处理，可以试试将蜂鸣器发声的相关程序放在定时器中断函数中。中。