Hi, these equipment presented fall into the classification of Electronic Musical Instruments, because through them you can create music from your recordings or audio tracks chosen. Even the gears that are part of the final achievement, such as an amplifier, a computer, an equalizer, etc., are also included.
A turntable used by a DJ is his musical instrument, but you can also use a cassette deck, a Tuner and any audio support, which you can then transform with creativity into another music or sound rhythm, changing its speed or adding effects.
A piano and an electric guitar, without an amplifier and speakers can not be heard, they all work as a team and depend on each other to give us that final sound.
The human voice, also works as a natural musical instrument, since with it many sounds are achieved.
There are not only musical instruments, the best known are: strings, wind and percussion. Every day we can add sources that emit sounds and make music.
There are musical bands, which are already making music and live shows, from their old recordings using Artificial Intelligence with Digital Avatars that copy their members. The field is expanding every day with development, and with it the musical instruments.

In life we can be doctors, musicians, writers, and whatever we like to do. That makes us grow more in all our levels of being.
Music is one of the most used Therapies within the Holistic Bioenergetic Techniques for the health of humans and other living beings. I have my collection, where I use each sound to help achieve the desired effect. It is a very interesting field, and in that sense, your doctor friend gave you his opinion.
Thank you for writing and motivating my response. Regards