"I Wish" and "Sir Duke" were the big hits from Songs In The Key Of Life, but "As," released as the last single from the classic album, holds up as one of Wonder's greatest accomplishments.

Running 7:07, the first half finds Stevie relating his love to nature's wonders: just as the earth revolves around the sun and the rosebuds bloom in May, his love will endure. It's a statement of faith, knowing that love and nature are the works of God.

Midway through, Wonder changes his voice, going into the gravely growl of a preacher to make a call to action:

Change your words into truths and then change that truth into love
And maybe our children's grandchildren and their great grandchildren will tell

The chorus then returns for a long and jubilant fadeout, "Hey Jude"-style.

There is some serious keyboard talent on this track, as Wonder and jazz great Herbie Hancock both played Fender Rhodes pianos, creating a sleek layered groove. Other musicians on the track were Nathan Watts on bass, Dean Parks on guitar, and Greg Brown on drums.

The radio edit was cut down to 3:27, removing the gospel-flavored bridge and the extended outro.

George Michael and Mary J. Blige released a cover version produced by Babyface in 1998 that appeared on Michael's compilation Ladies & Gentlemen The Best Of George Michael, but the track was left off US copies of the album. In 1999, it was released as a single in Europe and Australia, but not in the United States. This version went to #4 in the UK.

The duet was included on Mary J. Blige's 1999 album Mary and made #57 on the R&B chart due to airplay.

"As" was used in the 2006 Will & Grace episode "The Definition of Marriage," and in these movies:

The Best Man Holiday (2013)
Black Nativity (2013)
House of D (2004)
Snow Dogs (2002)
The Best Man (1999)