You should verify, that the command you are using really sends that header.
Using cURL it works just fine (see last line of output):
$ curl -H "Icy-MetaData: 1" -v "http://ice1.somafm.com/deepspaceone-128-mp3" >/dev/null % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* Trying 173.239.76.148... 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* Connected to ice1.somafm.com (173.239.76.148) port 80 (#0) > GET /deepspaceone-128-mp3 HTTP/1.1 > Host: ice1.somafm.com > User-Agent: curl/7.45.0 > Accept: */* > Icy-MetaData: 1 > * HTTP 1.0, assume close after body < HTTP/1.0 200 OK < Content-Type: audio/mpeg < Date: Mon, 25 Apr 2016 04:16:47 GMT < icy-br:128 < icy-genre:Ambient Space < icy-name:Deep Space One: Deep ambient electronic and space music. [SomaFM] < icy-notice1:<BR>This stream requires <a href="http://www.winamp.com/">Winamp</a><BR> < icy-notice2:SHOUTcast Distributed Network Audio Server/Linux v1.9.5<BR> < icy-pub:0 < icy-url:http://somafm.com < Server: Icecast 2.4.0-kh3 < Cache-Control: no-cache, no-store < Pragma: no-cache < Access-Control-Allow-Origin: * < Access-Control-Allow-Headers: Origin, Accept, X-Requested-With, Content-Type < Access-Control-Allow-Methods: GET, OPTIONS, HEAD < Connection: Close < Expires: Mon, 26 Jul 1997 05:00:00 GMT < icy-metaint:45000 <