Genes aren't the only factor. Because you inherit one APOE gene from your mother and another from your father, you have two copies of the APOE gene. Having at least one APOE e4 gene increases your risk of developing Alzheimer's disease. If you have two APOE e4 genes, your risk is even higher.
Compound Time Signatures In compound time signatures, the beat occurs on a dotted note and is divisible by three. The most common compound time signatures are 6/8, 9/8 12/8.
Western Musical Rhythms. European and other Western music uses a time signature, or meter signature, to measure the rhythm of a particular piece of music. One of the most frequently used time signatures in rock, blues and other forms of pop music is 4:4 time, also known as common time.