Beat vs Rhythm
The beat is the steady pulse underneath the music, but rhythm is the pattern of sounds that happens ON TOP of the beat. Beat and rhythm are different things!
Think of it this way: the beat is like your steady footsteps when you walk. The rhythm is like the words you say while walking. Your feet keep the same steady pace, but your words have their own pattern of long and short sounds.
Say the word 'watermelon' — WA-ter-mel-on. That word has four parts (syllables), each one a short sound. Now say 'go' — just one long sound. If you clap the rhythm of 'watermelon,' you clap four quick claps. If you clap 'go,' you hold one long clap.
Rhythm is the pattern of long sounds and short sounds in music. Some sounds are quick (short) and some sounds are held out (long). The combination of long and short sounds creates rhythm!