Where can I download a free synthesizer program?

You could try synthfont.
However, you will need soundfonts to make it sound good, but you can find links to some on the site.

They’re all over the place. My favorites (that are free) come from TAL. They’re a really gritty, bassy, analog type of sound, probably the best free softsynths you can find out there. Good for dubstep, house, anything that requires strong low end.

Otherwise there’s sites like these that index a bunch of plugins, free and paid.

Also, I’m assuming you have Ableton or Reason or Pro Tools or some sort of DAW to work with, otherwise those won’t be what you’re looking for.

Is fruityloops still around? That was a good one.

@dverhey
How do you get that to work? I’ve copied it to Vstplugins and now what?

@mowens – Fruityloops is now called FL Studio. It’s still good, although people have seemed… divided in the past regarding it’s step sequencer and general interface – I really like it; others loathe it.

@dverhey
I can’t install it what do I do?

@the100thmonkey Looks like you have to pay for it too. I could have sworn it was free.

@dotlin You need to have a plugin host, also known as a DAW for it to function. It’s not just a plug and play system.

My favorite DAW is Ableton Live but that does cost money, lots of money. @the100thmonkey was also talking about Fruity Loops (FL Studio) which is also really good, but, unfortunately, costly as well. So really, you can get the synthesizers and plugins very cheap, but the actual host for the plugins or DAW is quite costly, often with a large learning curve involved as well.

It’s not an easy business to get into. If you already have Ableton, Reason, FL Studio, Pro Tools, whatever, disregard and I’m sure Fluther can help you with those programs, but if you don’t have a plugin host and you seriously want to consider making music I’d recommend you buy one, or at least download the demo of Ableton or FL Studio.