In a 4/4 time signature, also known as common time, the beat with the strongest emphasis is the first beat. This is because the first beat is typically the downbeat, which provides the primary emphasis and sets the tempo for the rest of the piece. The second and third beats have slightly less emphasis, while the fourth beat is often the weakest in terms of emphasis. This strong emphasis on the first beat helps establish a steady and predictable rhythm in the music.
In a time signature of four-four, the meter indicates that there are four beats in each measure and the quarter note receives one beat. The strongest beat in a four-four time signature is typically the first beat of each measure. This is because the first beat often carries the downbeat, which is the emphasis or strong accent in the rhythm.