Brothers Johnson guitarist George Johnson wrote this song after deciding to dedicate himself to one girl instead of playing the field. He explained in The Billboard Book of #1 Rhythm & Blues Hits: "At the time I was seeing three young ladies. It got to the point where things were a little hectic, especially around Thanksgiving and Christmas time. I did the whole scenario of hopping from here to there and it got a little rough on me. I decided to write a song called 'I'll Be Good To You.' It was a commitment I decided to make for myself to one lady in particular - the lady that I wound up marrying, Debbie Johnson. I wrote it for her."
This was the first single from the first Brothers Johnson album, Look Out For #1. The brothers - guitarist George and bass player Louis - made a name for themselves playing on sessions for the likes of Bill Withers and Billy Preston. They got the attention of Quincy Jones, who brought them on tour and put them to work on his 1975 album Mellow Madness. Jones became their producer and helped them parse the hundreds of songs they had written down to nine for the album. "I'll Be Good To You" was their launching pad; the song was a big hit and earned them a Grammy nomination for Best New Artist (they lost to Starland Vocal Band). The album went Platinum, as did their next three, which were also produced by Jones.
Most Brothers Johnson songs have lead vocals by Louis, but George sang lead on this one. He never considered himself a vocalist, but Quincy Jones drew that out of him; George sang on Jones' Mellow Madness track "Is It Love That We're Missing?"
A friend of the band named Sonora Sam got a writing credit on this song along with George and Louis Johnson. She was at their house when they were working on the song and came up with the line, "The way we stand and the way we lie."
In 1989, Quincy Jones was working on his album Back On The Block, and decided to re-record this song with Chaka Khan. During the session, Jones' friend Ray Charles called Quincy and asked him to contribute vocals. The song was credited to "Quincy Jones featuring Ray Charles and Chaka Khan," and hit #21 in the UK and #18 in the US, where it also hit the top of the R&B charts for two weeks. It went on to win the 1990 Grammy Award for Best R&B Performance By A Duo Or Group With Vocal and the album Back On The Block won the 1990 Grammy for Album Of The Year.