The term 'KIND OF RECORDER' can be solved with the word 'ALTO', which is a four-letter word. An ALTO is a type of recorder, which is a woodwind musical instrument that is popular in early music and folk music. It is a cylindrical tube with finger holes and a mouthpiece, and produces a sound when air is blown through it. ALTO recorders are usually made of plastic or wood, and are typically pitched in the key of F.