I was listening to the radio on the way to work and the track that was playing had a lead sound that I though “I wonder if that’s made using an LFO”. So I have two questions:
1. I’m guessing an LFO runs through a time cycle to automate the oscillator and the rate change was making this sound I was hearing today?
The above then lead me on to my second question which is:
2. When listening to sounds; take me today, I was thinking how was that lead made - sine wave, square wave etc. Is there a list of sorts that says a square wave should be used for x, y but not really on z.
For the first LFO question, yes you’re essentially right there.
It is an oscillator just like any other only it can’t be heard as its only in the frequencies less than 20HZ. You can alter the delay rate and amount of the LFO. So it introdcues new harmonics into the overall waveform, and can often times result in a warbling or wavering sound or a tremolo. So in all likelihood that is probably what you heard.
As for the second question, that is a more in depth answer and I’m about to check out. But it comes down to harmonics, and sound associations. Square waves for example don’t have all the harmonics of a sawtooth wave, and generally sound “more hollow” which are great for “wood instrument” type sounds and also digital and even disco-ey bass sounds. But this is a large topic. I reccomend watching the video on synthesis 101 on the site.