No need for those tools! First of all, listen to Qianqianjing on your computer! Use Qianqianjingting to convert all the songs to be merged into MP3, requiring a constant bit rate! For example constant 160kbps. Then just use WINRAR. I think everyone has this software on their computer! Compress MP3 with WINRAR.

Select an MP3, right-click and select Add to Compressed File (A)-gt; then in the window that opens, change the "Compression Method" to Storage-gt; Change the compressed file name to .MP3 - gt; There is "Append" in the file, click it to add the second MP3, and add the third MP3 in the same way..., click OK after adding. Note that the file name in the general file should not overlap with the existing MP3, and the bit rate of each MP3 must be the same.