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GuitarFlex vs Session Guitarist

Session Guitarist and GuitarFlex both put a guitar in your music program on Windows, but they work in different ways. Session Guitarist is Native Instruments' collection of sampled guitars: ten titles, acoustic and electric, with recorded patterns played by session players, running inside the free Kontakt Player, on Windows and Mac. GuitarFlex is modeled, not sampled: presets for steel-string and nylon-string acoustic and electric clean, crunch and heavy guitars, an 18.2 MB download and a price of $79.

What they have in common

Windows 10 and 11, as a standalone program and as a VST3 plugin.
Acoustic and electric guitars, with reverb and EQ in each.
MIDI in. Both play MIDI you give them.

Where Session Guitarist stands out

Mac as well as Windows, with AU as well as VST3 and AAX through Kontakt Player.
Ten titles to choose from, $79 to $149 each, acoustic and electric.
Recorded patterns. Strummed Acoustic 2 has 163 patterns in 34 songs, and Picked Acoustic has 194. Session Guitarist turns a held chord into a guitar part; GuitarFlex plays the parts ComposerFlex writes, or any MIDI you give it.
Played from the keyboard. Hold chords or use auto-chord, and change rhythms and accents with key switches and the wheels. GuitarFlex has no keyswitches and no strum patterns, and does not strum by itself.
Extras. A Tap Rhythm Finder, separate bass patterns, a second instrument for your own lines, double-tracking and pedals in the electric titles.

Where GuitarFlex stands out

Nothing else to install. Session Guitarist needs the free Kontakt Player or Kontakt. GuitarFlex runs by itself.
Small. An 18.2 MB download that installs at 43.9 MB. Strummed Acoustic 2 is a 9.6 GB download.
No account, and it never goes online. A license key and your email address, entered once for each Windows user on each computer, with one license for one person, to use on all of their own computers. Native Instruments uses Native Access with an account, an internet connection to activate, and two computers at a time.
A demo. GuitarFlex has a demo you can download and try before you buy. Native Instruments publishes none for Session Guitarist.
One price. $79 covers every GuitarFlex preset, where Session Guitarist is sold title by title.
Your own settings. Over 70 sliders, and four slots (A to D) to switch between sounds or layer them.
Built to play ComposerFlex's songs, on the same PC with no setup, with down and up strums, open, palm-muted or dead, and Strum spread and Strum fall.

Which to pick

On a Mac: Session Guitarist.
To hold a chord and get a strummed or picked part, from recorded patterns: Session Guitarist.
On Windows, with no other program to install and no account: GuitarFlex.
To play ComposerFlex's parts, or your own MIDI, on an instrument you can shape: GuitarFlex.

Owning both

Session Guitarist brings ready-made patterns, and GuitarFlex brings a small instrument that plays whatever MIDI you hand it, so they can share a PC. GuitarFlex's demo is here; Native Instruments publishes no demo for Session Guitarist, so go by its pages on native-instruments.com. This page doesn't compare how they sound. That's for your ears.

The facts side by side

Every fact about Session Guitarist is from Native Instruments' own pages, checked on 7 November 2026. Prices are list prices in US dollars; sales come and go.

	GuitarFlex	Session Guitarist
How it makes its sound	Modeled. It computes every note as you play, from the physics of plucked strings: the acoustic presets sound through the guitar's body, and the electric presets through a pickup, an amp and a cabinet. It plays no recordings.	Sampled: guitars captured with microphones and played by studio musicians as recorded patterns (the maker's words), in the maker's Kontakt Player.
Price	$79, one-time	$79 to $149 each, by title: ten titles, from $79 (one electric title) through $99 to $149 (the deluxe titles)
Download and disk space	18.2 MB download, 43.9 MB installed	Strummed Acoustic 2: 9.6 GB download, about 16 GB uncompressed; the other titles read run from 6.3 GB to 8.6 GB download
Memory the maker asks for	4 GB, with 4 cores or more and 100 MB of disk (the minimum we state for every Flex program)	Not stated for the titles; Kontakt 8 Player lists 4 GB of RAM (6 GB recommended) and 2 GB of free disk for the player
Runs on	Windows 10 and 11, 64-bit	Kontakt 8 Player: Windows 10 or 11; macOS 14, 15 and 26
Forms	Standalone and VST3	Through Kontakt Player: standalone, VST3 and AAX on Windows; standalone, VST3, AU and AAX on Mac (64-bit only)
Needs another program	Nothing else	The free Kontakt Player, or the full Kontakt
Copy protection	A license key and your email address, entered once for each Windows user on each computer. No account and no online activation.	Native Access, with a Native ID account; an internet connection to download, install and activate, then offline
Computers per license	One license for one person, to use on all of their own computers	Two computers, not used at the same time (Native Instruments' license)
Demo	A demo to download and try before you buy	None published on the product pages
Guitars included	Presets in groups: steel-string and nylon-string acoustic, electric clean, crunch and heavy, and a two-guitar band preset; four slots to layer sounds	Ten titles, acoustic and electric. Recorded patterns played by session players: 163 patterns in 34 songs in Strummed Acoustic 2 and 194 in Picked Acoustic. Chords played from the keyboard or an auto-chord mode; key switches, mod wheel and pitch wheel change rhythms, voicings and accents; a Tap Rhythm Finder; separate bass patterns; a second instrument for your own lines; double-tracking, fret noise, convolution reverb, and pedals in the electric titles; MIDI drag and drop and NKS support

More: virtual guitars compared: modeled and sampled, a table of 25 products, and all about GuitarFlex.

If something here is out of date, write to [email protected] and we'll correct it.

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