There are multiple artists with this name:

1) The Portal was an old name for Dutch symphonic metalband Within Temptation. The band recorded some rehearsal tracks under this name. They are VERY hard to find.

2) The Portal is a cosmic rock show, helmed by Xavier Onassis, Gilly Gonzales, Jon Sousa, Chris Kelly, and Zarah Mahler. Inspired by sources such as Pink Floyd, Kan Nal, and Kahlil Gibran, The Portal infuses epic rock with tribal and body-shaking beats.

The Portal weaves together live-music, cinematography, lighting and performance to create an epic, mythological journey into the heart of humanity. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.