In music theory we learn that what makes a minor scale different from a major scale is that the minor scale contains a flat 3rd and, depending on the type, sometimes a flat 6th and/or a flat 7th. So to make an 8-note major scale minor, you lower the pitch of the third, sixth and seventh notes by a half step. A half step translates to one fret on the guitar, or one key on the piano. Understanding the technical theory and the shapes to make with your hands to play the scales and chords on your instrument is one thing, and congratulations to you if you're at all proficient with that aspect, but the further (and maybe more valuable) challenge is to be able to hear and recognize the different intervals.
This may be a fool's errand, but let's see if I can talk about what the intervals sound like: The notes in a major scale are typically described as consonant or resolute. When a note deviates from this consonance, it is described as having dissonance or tension. It is from this tension that we interpret the feeling the music gives us. Minor scales and the chords derived from them are usually associated with a kind of sad or dark mood. You may have heard the phrase "blue note" that frequently characterizes blues and jazz music. The literal note that creates that feeling is very often the flat 3rd or flat 7th of a minor scale. I'm not sure how else to describe these sounds but as feelings. I don't know if people who are skilled (either naturally or by training) at differentiating intervals in music "feel" the notes or just recognize them like faces. (I know some people literally see them as colors.)
I tell you all of this by way of explaining why the songs on MajorScaled TV sound weird. According to its Facebook page, MajorScaled TV digitally modifies minor scale songs to major scale. You may not be trained or practiced at recognizing minor intervals in music, but boy is it glaring when they're taken away. Metallica's "Nothing else matters," above, for example, loses its gravity. The one drawing some viral attention lately is modified REM called "Recovering my religion," oddly drained of its melancholy. Music on anti-depressants.
Ok music geeks, the comments are yours. Do your worst.
[Not quite related: That choral version of Nothing Else Matters that we hear all the time in the Zero Dark Thirty commercial that airs during the Maddow show (but not in the actual movie?) is by Scala & Kolacny Brothers who do some other fun covers as well.]