This patch shows a simple method for mixing and viewing two sine tones generated by the cycle~ object.
To generate a series of numbers in Max that outline a sinusoidal shape, you can use the sin() function in the expr object. As the argument in the sin() function goes from 0 to 2π (6.283185), the output will be the sine of that value, going from 0 up to 1, down to -1, and back up to 0. So, by feeding a series of numbers into expr, you can generate numbers that follow that sinusoidal pattern.
How would you go about playing a melody (or arpeggio) that has a sinusoidal shape? Using a steadily increasing number, you can step repeatedly through a sine function stored in a lookup table, and then scale and offset the result to be in the desired pitch range.