What can be used to record the piano sound without noise? Do I need a tape recorder or a mobile app? Thank you.

Professional recording requires several condenser microphones, mixers, etc.

The easiest way is to record with a video camera and then delete the video. It's convenient, the sound quality is enough, and it's stereo recording, and so is the camera, depending on the grade.

If you have electrical steel, you usually have your own recording function, and the card can be recorded directly in the card. This is an internal recording and the effect is very good.

Mobile phone recording is ok, but it is mono, and the bass of the mobile phone is not very good.

Recording pens are not impossible, nor are low-grade ones. Generally, it is better to spend more than 1000 yuan. Turn off AGC function.

Choose the time and place to record the piano and try not to reduce the noise. Missing details will affect the timbre, and untrained people can hear it. Among musical instruments, people are most sensitive to the timbre of the piano.

Another point is that the distance between the recording equipment and the piano cannot be distorted at the loudest place. This should be adjusted by distance, and all AGC or ALC functions should be turned off. The recording equipment with level indicator should control the maximum volume not to exceed -3 dB. Because the range from -3 dB to 0 dB is difficult to control, it will be distorted after 0, so it depends on the distance to adjust.