Jleraan, you right if is applied it shouldn't sound off, and anything that sounds off is pretty easy to remedy. Playing the major pent over a major pent does sound more in unison, giving th quote "playing with the harmony". While playing the minor pent over a major progression does dound contrasting, giving the quote "playing against the harmony". Just in case you ever hear those terms again, you'll know what they mean.

Death metal with happy solos = In flames "lol" don't get me wrong I love this band, but there solo always seem happy. Some of their songs too, especially over the last few years.