According to the digital sheet music published at Musicnotes.com by Universal Music Publishing Group, "What I Want" was originally composed in the key of E major and set to a "driving rock" tempo of 140 BPM.
As stated in the digital sheet music published at Musicnotes.com by Universal Music Publishing Group, "What I Want" was initially composed in the key of E major and set to a "driving rock" tempo of 140 BPM.