• Adding More Instruments to Garageband Garageband makes it really easy to get in there and easily set up virtual instruments that come built-in. However, if you're going in to Garageband with the intention of using a third-party plug-in, you might be scrat.
• 12 String Chords guitarGarageBand's Jam Pack 1add-on comes with a lot of great additional Software Instruments, Effects and Loops. One of the new instruments, the 12 String Chords Guitar, emulates a person strumming guitar chords instead of playing an individual note. There are a total of 24 chords, 12 major & 12 minor chords.

Audio Units

Audio Units can be added to GarageBand to give you many more instruments to play with.

Apr 20, 2006 Boldt 24-Pack is a package of 24 software instruments for GarageBand / Logic. Boldt 24-Pack is free to use as much as you want, but if you would like to make a donation to help me cover any possible bandwidth costs or if you want to give me some incentive to make more of these packages, the download contains my PayPal address. 1) The Steinway Grand Piano. This is the stock piano that comes with Garageband. When you first open up Garageband and select “Software Instrument,” and the interface opens up on your screen, you’ll be given the option on the left-hand side: “Piano,” and then “Steinway Grand Piano.”.

Here are some good sources for Audio Units

1. One of the largest makers of Audio Units and other GarageBand plug-ins is AMG.
   
2. MDA-VST: Which contrary to its name has over a dozen AU plugins includung Amp Sims, Detuner, Delay, Comperssor/Limiter, and more
   
3. MacMusic.org: a HUGE list of Freeware, Shareware and Commercial Plug-Ins.

TheGarageDoor Image Gallery

SoundFonts

There are literally thousands of SF2s available on the web. In fact if you google 'SoundFont' you'll find more hits than you could probably look through in a lifetime. SoundFonts page.
SoundFont sources:
sf2midi.com presents a massive collection: At last count over 3,860 free SoundFonts available!
Hammersound
Tons of SoundsFonts nicely categorized. just shy of 1,100! (Piano, Chromatic Percussion, Organ, Guitar, Bass, Solo Strings, Ensemble, Brass, Reed, Pipe, Synth Lead, Synth Pad, Synth Effects, Ethnic, Percussive, Sound Effects, Drumkits and percussive kits, Collections, Miscellaneous)

Fox-gieg
Over 220 nicely categorized SoundFonts (Bass, Brass, Guitar, Loops (not loops like GB loops, actual instruments that paly sequences), noise, Orch Hit, Organ, Perc, Piano, Strings, Synth, Voice, Wind)
The Jazz Page
Muted Trumpet, Trombone, Flute, Trumpet, Brass, Tenor Sax, Acoustic Bass, Contrabass, Harmonica, Soprano Sax, Alto Sax. Guitars: Jazzguitar, Nylon Guitar, Steel Guitar, Clean Guitar, Muted Guitar, Overdrive Guitar, Distortion Guitar, Guitar Harmonics.

Software

MidiKeys
MidiKeys is a small application for Mac OS X that presents a miniature MIDI keyboard onscreen. You can use the computer keyboard to play MIDI notes, or click on the keys with the mouse. There is also an option to select a MIDI source and see incoming notes played on the keyboard.

iDrum adds the missing ingredient to your Mac-based home recording studio - a fully programmable drum machine. It's just as easy to use as the hardware drum machines of yesteryear, but with all the flexibility of a software-based virtual instrument. iDrum integrates seamlessly with GarageBand - or you can run it as a standalone application. Create drum patterns in iDrum right alongside your existing tracks, perfectly in time, all the time. Or use iDrum as the backbeat when you're laying down new tracks. Use the hundreds of included pre-programmed patterns and rhythms or roll your own. The price is a very reasonable $49.
Download Demo - The iDrum Demo Version is identical to the full version except that it will time-out ten days after you install it. It includes Audio Unit and Standalone versions of iDrum.
Free Beats
From the same company comes the offer of

Boldt Software Instruments For Garageband 2020

74 FREE iDrum beats for GarageBand.

Garageband Audio Units