You don't have to be a Toscanini to make music with your child

Even small babies respond to music. And one- and two-year-olds are delighted with simple songs and games that enable them to sing, clap, do finger-plays, and move their bodies to rhythm.

Tom Glazer, a well-known balladeer with guitar, has been singing to children for 30 years and is considered an expert in the kind of songs that most please them. He has spent his adult life collecting such songs from many sources, performing concerts, making records, and writing books on this subject.

Because parents are becoming more aware of the importance of encouraging very young children to express themselves through words and music, Mr. Glazer's advice to them boils down to this: Keep it all simple. ''It cannot be overemphasized,'' he stated in an interview, ''that the key to a child's pleasure in songs and games is simplicity, generated by genuine pleasure in and love for the child himself. If these elements are present, everything beautiful follows.''

His next plea to parents is that they set aside their own inhibitions and learn to perform freely and joyfully with their children. ''A lot of people think only a gifted person can do music,'' the Philadelphia troubadour says. ''This is not true at all. Anybody can do music. You don't have to be a Rubinstein or a Toscanini. You don't even have to be in tune. You can sing off-key, but if you are just being you, your child will enjoy your musicmaking.''

Being able to play a piano or other musical instrument is not necessary either, says Mr. Glazer. A parent can sing, hum, clap, or dance out rhythms, and a child will be enchanted by such a down-to-earth approach. A child loves this complete attention, he finds, and the interaction with a parent, particularly, but also with other children, relatives, or friends.

''Pick out just the melody alone, if you can, or have someone do it for you, '' he suggests. ''Use rhythm instruments if you have no notemaking experience. Or utilize the many good records and tapes that are on the market.''

The author-musician says his own two most popular records are for the youngest children, ''Let's Sing Fingerplays'' and ''Music for Ones and Twos'' (CMS Records). His fifth book, ''Music for Ones and Twos: Songs and Games for the Very Young Child'' (Doubleday, $7.95 paper), puts between covers the words, simple piano arrangements, and guitar chords of some 60 songs, fingerplays, and games.

The book includes such classics as ''This Little Pig,'' ''I'm a Little Teapot ,'' ''Here Is the Church,'' ''Pat-a-Cake,'' ''Hickory Dickory Dock,'' and ''Bye, Baby Bunting.'' And folk songs always appeal, he finds, because they are musical miniatures of life itself, and children react to their simplicity, humor, and catchy tunes.

Yet he cautions parents to use any such book only as a point of departure. ''Be flexible, be creative, invent,'' he says. ''Make up your own games, songs, and bits of play. You will be amazed at your own ingenuity. This kind of contact is enormously important to the development and education of children. And it gives parents tremendous insights as to what delights a child. Even if you bounce a baby or toddler on your knee in time to music, that is a wonderful game in itself, and a joyful introduction to music.''

Working mothers or single parents should not leave music entirely to the nursery school or day-care center, says Mr. Glazer. Enjoying music together is a means of sharing affection and demonstrating understanding, so even the busiest parent should make the time for it.

Amy Dombrow, who works with babies and very young children at the Family Center of the Bank Street College of Education in New York, agrees. ''We let six-month-old babies sit at the side and observe the teacher and the other children as they sing, clap, and move, and the babies love it,'' she says. ''Often by the time they are 10 or 11 months old, they are beginning to copy with their fingers the gestures of 'Eentsy-Weentsy Spider.' And they begin to make the sounds of music even before they can talk.''

She notes that parents must be relaxed in working with small children to get the best and most enjoyable results. ''If a parent is thinking, 'Now I've got to spend 20 minutes doing music with Johnny' and is all stiff and starchy about it, the sense of fun, spontaneity, and participation will be missing. Children know when parents aren't having any fun.''

Fun is exactly what Peggy and Gordon Imrie share with their 21/2-year-old son , John. Peggy is a professional singer and plays piano; her husband plays guitar. They make music frequently, to their son's delight, and each night at bedtime they sing four or five songs to him.

Once a week mother and son attend a singing class in the neighborhood, along with four or five other mothers and children, and the whole group sings together.

Tom Glazer sums up: ''The quintessential factor underlying using music with children is simply this: If we love children, we very quickly know what to do with them in teaching or in entertaining them; but if we don't love them, no one can teach us what to do.''