WeChat.ServerMessage.XmlMessage.reply_music

You're seeing just the function reply_music, go back to WeChat.ServerMessage.XmlMessage module for more information.
Link to this function

reply_music(to_openid, from_wx_no, timestamp, title, desc, music_url, hq_music_url, thumb_media_id)

回复音乐消息 - 官方文档

<xml>
  <ToUserName><![CDATA[toUser]]></ToUserName>
  <FromUserName><![CDATA[fromUser]]></FromUserName>
  <CreateTime>12345678</CreateTime>
  <MsgType>music</MsgType>
  <Music>
    <Title><![CDATA[title]]></Title>
    <Description><![CDATA[description]]></Description>
    <MusicUrl><![CDATA[MUSIC_Url]]></MusicUrl>
    <HQMusicUrl><![CDATA[HQ_MUSIC_Url]]></HQMusicUrl>
    <ThumbMediaId><![CDATA[media_id]]></ThumbMediaId>
  </Music>
</xml>