Creating a Music Video will give your music mass exposure more so than the User Showcase or SoundCloud.
There's some links below you can check out for submitting your music videos to TV/Cable channels.
Before submitting, get your song/s up on iTunes and other Digital Music stores first.
You can use sites like www.tunecore.com to distribute them them.

Here's a few ways to get your Music Videos out there:

https://vydia.com/

https://www.musicindustryhowto.com/how-to-get-your-music-video-on-mtv/

http://viewmaniac.com/services/music-video-submission/

http://www.mtv.com.au/upload#mtv-upload-get-your-music-video-on-mtv

https://www.musicindustryhowto.com/making-music-videos-on-a-budget-the-ultimate-guide/

http://www.mtvbase.com/info/video-submission-guidelines

http://www.fastrax.co.uk/

http://www.abc.net.au/rage/submissions/

just do a google search for more...