Make a list of classic composers and assign one to each student. Have each student research the life and music of their assigned composer and write a few short paragraphs answering questions about the composer's life and music. Have students copy or download a picture of the composer. Ask them to listen to selections of music from their composer and choose a music clip to share with the class. Give students class time to share their research and clip of music chosen with the class. Have the students decorate the page with their report and create a bulletin board display with their composer pictures and reports.
Gather clips from a variety of musical instruments. Play the clips to the class, identifying each instrument. Provide a handout sheet for the third grade class with a list of the musical instruments you'll be using. Mix up the clips, playing one and asking the students to identify the instrument. Those who correctly identify the instrument receive a credit. Play the clips until most of the students identify instruments from their sound. Next play music from different composers that feature a variety of musical instruments. Have students identify what instruments they hear.
Have each third grade student sing a short chorus of a song so you can hear the student's voice. Introduce songs to the class such as "America the Beautiful," "B-I-N-G-O," "Yankee Doodle," or "Down in the Valley." Sing the songs with the students until they are comfortable with the lyrics. Change things up with high voices singing different parts than lower voices. Teach students to sing parts. Record the result so the students hear the improvement. Have them listen to their voice and to the voices around them.
Introduce songs with actions such as the "Hokey Pokey," which is a good action song, or invent actions to go with the songs you teach the class. Using music and actions, encourage the third grade students to move and have fun. Have the students play musical chairs with one chair less than the number of students. Play music. When you stop the music, the students find a chair. The student without a chair is out. Remove a chair and continue until only one chair remains.
Ask the third grade students to close their eyes as you play music and simply move to the music. Balance classical music with more modern music and slow as well as more fast-paced beats. Allow the students to free-form dance as they "feel" the music. Afterward ask them write down or draw a picture of how they felt as they moved.