Contemporary instrumental music was informed by the aesthetics of new age's progressive electronic wing, but drew from a wider range of emotions and styles. Where progressive electronic emphasized lush, elaborate, and often grandiose compositions, contemporary instrumental was just as free to settle into simple, quiet rumination, or to prominently feature soloists in addition to accessible melodies. Contemporary instrumental also made greater, sometimes exclusive use of acoustic instruments, particularly when artists wanted to create mellow, pleasant moods. The recordings of pianist George Winston helped establish this direction during the early '80s. Not all contemporary instrumental artists share new age philosophies, even if their music frequently draws upon similar feelings and influences; moreover, contemporary instrumental music may employ bits of pop, rock, jazz, folk, classical, and world music (when the latter is especially prevalent, it's termed ethnic fusion). Nevertheless, the '80s and '90s continued to witness a high degree of crossover between progressive electronic, the similar adult alternative style (which was more electro-acoustic), and contemporary instrumental, with many artists fitting simultaneously into more than one category.
Some artists are not cool about Karaoke
There's nothing in copyright law that says you have to allow an "instrumental" version of your music and the lyrics cannot be embedded in a digital file without artist permission either. If the artist says "no karaoke" you'll only get that track from a karaoke company who aren't bothering with copyrights and paying royalties.