I've always used madplay to play internet streams on my router, but it is very sensitive to internet gaps, also madplay does not have any buffer, a better alternative is mpg123
madplay:
/usr/bin/wget -O - http://webradio.antennevorarlberg.at:80/partymix | /usr/bin/madplay --replay-gain=audiophile --attenuate=-0 -
mpg123:
/usr/bin/wget -O - http://webradio.antennevorarlberg.at:80/partymix | /usr/bin/mpg123 --buffer 2048 --preload 1 --rva-audiophile --timeout 0 -