whilst 'what's going on' is considered by most to be his finest work,'let's get it on' was an amazing follow-up,and my personal favourite.it only lasts for half an hour,but what a half hour!every song is a gem,his voice never sounded better,and the finale 'just to keep you satisfied',(about his marriage breakdown)is the best song he has ever written,with the pain pouring out of every note he sings.a soul masterpiece!