As a critic, Landau wrote for Rolling Stone from its first issue and for other publications. In Volume 1, Number 1 of Rolling Stone, published on November 9, 1967, Landau compared Jimi Hendrix and his debut album, Are You Experienced, to Eric Clapton and Cream's debut album, Fresh Cream (both released months before, and both Hendrix and Cream having made huge American splashes as live performers that summer). The next few issues saw Landau staking out more traditional R&B and soul territory with profiles of Aretha Franklin, and Sam and Dave, plus a posthumous Otis Redding appreciation.

Landau's 1974 article in The Real Paper, wherein he claimed, "I saw rock and roll's Future and its name is Bruce Springsteen," is credited by Nick Hornby and others with fostering Springsteen's popularity. Landau was then hired by Springsteen, and is cited as co-producer on Springsteen studio records from 1975's Born to Run through 1992's Human Touch and Lucky Town. Landau is considered to have influenced Springsteen artistically as well as professionally.

In 2011, Landau had a growth in his brain surgically removed. The surgery resulted in the loss of sight in one eye.

Landau has been responsible for the liner notes for The Atlantic Albums Collection by Aretha Franklin (2015), Soul Manifesto: 1964-1970 by Otis Redding (2015), and The Complete Atlantic Albums Collection by Wilson Pickett (2017).