There are several other instruments which are related to the piano which are important for us to introduce to school students. They are the organ, celesta and harpsichord.
Show and talk about the different aspects and characteristics of the keyboard instruments. The instruments are mainly similar in the way that they are laid out. The keyboard layout is the same in all of these instruments. However if we are to be technical about it each of these instruments really belongs in a different family.
The harpsichord and the piano are string instruments (chordophones). The harpsichord mechanism plucks the strings while the piano mechanism strikes the strings. (In this respect the harpsichord is like a guitar and the piano is like a hammered dulcimer.)
The pipe organ is actually a series of wind instruments (aerophones). Some pipes operate like a flute, other pipes operate like a whistle or recorder, and yet other pipes operate like a reed instrument.
The keyboard on the celesta plays bells, just like the Glockenspiel, hence why it can be called a “bell piano”
The music lesson plans on instruments of the orchestra includes lots more of this interesting trivia.
Perhaps you might also discuss these things: the piano and the celesta have a single manual (row of keys), whereas some harpsichords and virtually all organs have multiple manuals. Pianos and organs have a very wide range while harpsichords and celestas have a more limited range.