What is the difference among the musical instruments? Are they different slightly?

1. pipe 2. flute 3. recorder

1. There are many kinds of pipes, with many different sounds.

https://www.google.com/search?q=playing+the+pipes&oq=playing+the+pipes&aqs=chrome..69i57j0l5.2953j0j7&sourceid=chrome&ie=UTF-8

2. The flute has a range of sounds:
https://www.vsl.co.at/en/Concert_flute/Sound_Characteristics

3. The recorders that I've heard have lower tones than the flutes.
https://www.google.com/search?q=sounds+of+recorder&oq=sounds+of+recorder&aqs=chrome..69i57j0l5.5256j0j7&sourceid=chrome&ie=UTF-8

I'll give you a fourth -- the piccolo. It's noticeably higher than any of the others.
https://www.youtube.com/watch?v=3EFLa5dK-nU

The three musical instruments you mentioned - pipe, flute, and recorder - are all classified as woodwind instruments, meaning that they produce sound by the player blowing air into a tube or against an edge. Although they belong to the same instrument family and share some similarities, there are distinct differences among them.

1. Pipe: The term "pipe" is quite broad and can refer to various types of musical instruments. In general, a pipe consists of a tube or multiple tubes through which air or steam is passed to produce sound. Examples of pipes include organ pipes, bagpipes, and pan pipes. The construction and playing techniques can differ significantly depending on the specific type of pipe.

2. Flute: The flute is a cylindrical or conical tube with finger holes and a mouthpiece. It is typically made from metal, wood, or plastic. Flutes are played by blowing air across a hole in the instrument's side, creating vibrations and producing sound. The player changes the pitch by covering or uncovering the finger holes to alter the length of the vibrating air column. Flutes can have different sizes and variations, such as the standard concert flute, piccolo, or Native American flute.

3. Recorder: The recorder is a specific type of flute, with a distinct design and sound. It has a recorder mouthpiece (fipple) at one end and finger holes along the length of the instrument. Recorders are usually made of wood, though plastic ones are also available. To produce sound on a recorder, the player blows into the fipple, which creates a stream of air across a sharp edge. By covering or uncovering the finger holes, the player can change the pitch and produce different notes.

While all three instruments belong to the same woodwind family and share the basic principle of producing sound through blowing air, their specific designs, playing techniques, and sounds are different. It is worth noting that there are many other musical instruments in addition to these three, each with its own unique characteristics and sound-producing mechanisms.