Upon being telephoned by Jones, requesting that the guitarist participate on the track, Van Halen thought he was receiving a prank call. Having established that the call was genuine, Van Halen recorded his guitar solo free of any charge. “I did it as a favour”, the musician later said. “I was a complete fool, according to the rest of the band, our manager and everyone else. I was not used. I knew what i was doing, i don’t do something unless I want to do it. Van Halen recorded his contribution following Jones and Jackson arriving at the guitarist’s house with a “skeleton version” of the song. Fellow guitarist Steve Lukather recalled, “Initially, we rocked it out as Eddie had played a good solo, but Quincy thought it was too tough. So i had to reduce the distorted guitar sound and that is what was released. On the record, as Van Halen’s guitar solo begins, a noise is heard that sounds like somebody knocking at a door. It is reported that the knock was a person walking into Van Halen’s recording studio. Another story has claimed that the sound was simply the musician knocking on his own guitar.
this is unofficial Youtube video compiled with “Eddie Van Halen” images for promotional purpose.