Answer:
Many people play a musical instrument music can be soothing. A lot of schools teach the recorder; it is inexpensive and easy to play. The guitar is another excellent instrument for beginners, it takes more practice than a recorder.
What type of error is present in the underlined sentence? 
✔ run-on
Which is the best revision to fix the error? 
✔ adding a semicolon after instrument
Explanation: