Looking at some clips online and listening to some music, I’ve noticed that some songs in the 1970s had a very unique type of instrument in them that has some sort of “baroquey” sound to it. It’s probably most notable (and well-known) in the Partridge Family’s I Think I Love You (it can be heard in the back of the entire song and even gets its own solo), but I’ve also heard the instrument- or an instrument like it- in other places of the same vintage, such as this promo for the MPAA’s rating system and this cartoon which was added, much to the anger of director Roman Polanski, to the American release of the film Dance of the Vampire (which was retitled The Fearless Vampire Killers or Pardon Me, But Your Teeth Are In My Neck).
What is this instrument? Is it the same instrument in all three of these clips (some of them sound different from the others)?
Although it’s the same sound, that’s not actually a harpsichord or clavichord - it’s a regular piano that’s been played back at double-time. George Harrison discovered that he wasn’t able to play that segment fast enough to keep up with the tempo, so it was recorded and sped up for the track, which created the harpsichord effect.