Your server (lecion.blob.core.windows.net) is probably sending the wrong mime types for the mp3-file. You have to add audio/mpeg3 as mime type for .mp3 files.
you have to do this on the server. If it supports .NET you can do this in a web.config file.
<configuration>
<system.webserver>
<staticcontent>
<mimemap fileextension=".mp3" mimetype="audio/mpeg3" />
</staticcontent>
</system.webserver>
</configuration>