Since you folks are reminding me of songs from the 1974 era that I've long wondered about, here's another.
I heard this song on a radio that some guys were playing at a campout in San Onofre in California, which is in San Diego County but so close to Orange County that it's more likely the song was from some Orange County station. It was a rock song that I thought was by Led Zeppelin, but since then I've heard all the Led Zeppelin albums, and that isn't the correct group. It had a male vocalist, though. I don't remember any particularly high vocals or remarkable vocal harmonies in the mystery song, though there may have been some.
The main thing I remember about the song is that it had a guitar riff throughout that was stolen almost verbatim from the Rolling Stones song "Jumpin' Jack Flash" (1968) (http://www.youtube.com/watch?v=e9XKVTNs1g4). The riff played throughout the verses of the song, placed in rhythm exactly as it is in JJF, but the riff ended slightly differently from the Stones riff, more like the riff in Peter Frampton's version of JJF (1976), which also ends slightly differently (http://www.youtube.com/watch?v=q9Wz_RnmYwg) than the Stones riff. The song had a strongly emphasized 2nd beat of each bar, emphasized on that beat with a drum hit and a slammed major chord on electric guitar, I believe, more emphasized on that beat than in JJF. It was a pretty decent rock song. It was somewhat slower than JJF, I believe about the speed of Frampton's version of JJF in the above YouTube link. It was all in 4/4 time like most rock songs.
This song was played in summer 1974. Another song I remember that was played on their radio that night was "Bennie and the Jets" (Elton John, 1974), which further confirms the year. I had never heard that mystery rock song before or after in my life. I assumed it was a song I would hear again someday but never did, unfortunately.
There must be extremely few rock songs up to that time that are that similar to JJF yet that are clearly distinct, so the song should be clearly identifiable *if* somebody happens to recognize it from this description. Let's hope...