Is Native Instruments' virtual picked acoustic guitar better than the real thing?
Picked Acoustic is the latest in NI's Session Guitarist series of virtual guitar instruments. For those unfamiliar with the range, let's begin with a quick recap. Winding the clock back to 2015, Daniel Scholz and Samuel Dalferth teamed up with Native Instruments to release Session Guitarist Strummed Acoustic, a Kontakt instrument comprising a collection of strummed guitar performances played in different styles, with various patterns provided for each style. Featuring a sampled vintage Martin D‑35, its patterns are derived from real-life performances, accurately transcribed into MIDI data. Chords played on a MIDI keyboard are converted to guitaristic voicings and tempo-sync'ed to the host DAW. Up to eight patterns can be mixed and matched from any of the styles to create custom 'songs' and triggered by keyswitches. Additional touches such as doubling, string squeaks, fret noises, body slaps, endings, low and high voicings and effects bring further realism. The key benefits of the concept are quick and easy arranging of guitar parts, with consistency of sound and performance, the latter often being time-consuming to master on virtual guitar instruments that require manual input of the strumming movements.
The original Strummed Acoustic was reviewed in SOS January 2016 issue. Strummed Acoustic 2 followed, featuring two guitars: a small-bodied Martin O-17 mahogany six-string, and a Guild F‑412 12-string, each with their own 'suites' of song styles and patterns.
Session Guitarist Picked Acoustic (henceforth referred to as PA) takes a similar approach, this time focusing primarily on a finger-picking playing style. This library offers several enhancements over its strummed predecessors, the most significant being control over the harmonic content of patterns, and the freedom to play exactly the melodic parts you want. PA achieves this with two separate NKIs, Picked Acoustic and Picked Acoustic (Melody); both feature a beautifully recorded vintage Martin 00-21 steel-string — clean, clear and full-bodied with bags of sustain and detail. From their specially developed miking techniques to the amount of vintage and high-end gear involved in the sampling, the developers have clearly put a lot of effort into getting it right.
The Picked Acoustic.nki instrument operates similarly to the Strummed Acoustics, having 37 Song styles and up to six patterns for each style. Selecting a Song loads its associated pattern variations (up to six of them); eight pattern slots are provided, each slot corresponding to one of the keyswitches C1—G1. There are always at least two vacant slots available to contain additional patterns, either 'tweaked' variations from the current Style or others culled from different Styles. Loading a Song also loads a corresponding Sound Preset if the 'Link to Song' option is lit; these contain effects appropriate to the Song style.
So far, this follows the Strummed Acoustics model, but PA has a new feature: chord-voicing options. A drop-down list of five preset chord voicings shows the relative pitches that will be played if a single key is pressed. As you play additional notes to build a chord, each voicing follows its particular rules but adjusts the harmonies wherever possible. If a particular voicing doesn't allow for certain notes, another probably will. Although PA includes a number of strummed patterns, the finger-picking patterns predominate and provide the most fun and musical interest, and for these the most rewarding option is the 'As Played' voicing. This gives the flexibility to play exactly the chords and inversions you want, no matter how abstruse — the patterns still provide the rhythmical framework, but you have complete freedom of harmonic movement. Walking bass lines, moving internal parts and leading voices bring a natural and convincing flow, as if the part is coming from the hands of a skilled player. Playing fewer notes reduces a pattern to a simplified version using fewer strings; add more notes (no more than six, mind!) and the pattern brings more strings into play, increasing in complexity. It's absorbing and quite addictive.
Many would struggle to record an acoustic guitar as well as this without access to a top–quality instrument, expensive microphones and high-end audio converters, not to mention the right recording environment.
The Pattern browser provides filtering options to help narrow the search for suitable candidates; you can search by picking style, pattern type and time signature. Curiously, the 'Riff' type and 3/4 time-signature filters return no results. Perhaps this suggests plans to include such patterns in an expansion pack or as a future update. To further assist in identifying suitable patterns, the browser's Rhythm Search tool enables you to tap in the rhythm you're looking for using a keyboard, and PA returns a list of the closest matches in order of relevance. Whilst PA's patterns are all provided in 4/4 (32 steps) or 4/4 triplets (24 steps), any non-compound time-signature can be realised by simply shortening their lengths to an appropriate number of steps. Although the patterns' rhythmical content can't be edited or created from scratch, the Shift function offsets them from up to -15 to +16 steps causing the rhythmical emphasis to fall in different places, changing the feel. You can also 'focus in' on a particular detail you like by shortening and/or offsetting the pattern so that detail falls at the desired position in the bar. Playing new chords with a high velocity generates an upward or downward slide, depending on the pitch of the previously played chord. Patterns' dynamics can also be smoothly varied in real time via the Impact slider, controlled by the pitch wheel.
Patterns are individually customisable in further ways; there's a choice of fingered or plectrum playing styles in Open, Muted and Flageolet (harmonics) flavours. The volume of each pattern can be offset relative to the others, and fret position can be adjusted (depending on the chord's played pitch on the keyboard) from a full-bodied open string tone to higher up the neck for a warmer, more muted tone. Each pattern's tempo can also be halved or doubled relative to the host tempo — speaking of which, PA's tempo range is exceptionally wide. Although the manual quotes a lowest speed of 65 bpm, which does seem to be the limit of the strummed patterns, I had most of the picking patterns running quite happily down at 26 bpm, with some even managing to achieve a mind-numbingly slow 20 bpm, and all the way up to a blistering 400 bpm. As no time-stretching is involved, sound quality remains pristine even at funereal extremes.
As flexible as the patterns can be, they don't address the need to play something more specific. The Picked Acoustic (Melody) instrument provides the solution, combining patterns and a freely playable version of the guitar in one NKI patch. The lower part of the GUI is divided into two — the 'playable' guitar is on the left, with four articulations: Open, Muted, Flageolet and Tremolo, assigned to the yellow keyswitches. Below those are two switches offering a choice of Plectrum/Finger-picking styles, and monophonic or polyphonic behaviour. When playing single-note melodies in Monophonic mode, overlapped notes produce hammer-ons and pull-offs; press the B1 keyswitch before playing a note and you get an upward or downward three-semitone slide into the note, depending on the pitch of the previously played note. Unfortunately you can't change the three semitones to one or two, which would give a more musical effect when transitioning between smaller intervals. Alternatively, upward and downward 'fading' slides can be triggered by keyswitches after a note is played.
When carefully placed, these create a natural flow between wider intervals and can also be used as 'fall-off' effects at the end of a phrase — slow or fast variations are triggered according to keyswitch velocity. Vibrato is available on the mod wheel as expected, but I'd always recommend performing it manually on the pitch wheel — the difference in realism is not to be underestimated. In polyphonic mode I really began to appreciate the warm, almost lute-like finger-picked style and the clear, incisive plectrum tone of the guitar. It's even possible, with a bit of careful post editing, to invoke hammer-ons and pull-offs in poly mode if you get the velocities just right and overlap notes ever so slightly. The delicate tones of the finger-plucked Flageolets provide an intriguing alternative to a harp — add a touch of modulated delay and reverb 'splosh' for extra magic. The Tremolos, which have a cyclical dynamic ebb and flow, make atmospheric ensemble pads with movement and interest, though one caveat is that they have no means of dynamic control (PA does not respond to CC7 or CC11). As the mod wheel is redundant on the Tremolos, it would be nice to see that used to control a combination of volume and filter cutoff frequency for that particular articulation. I would make only one other update request for the Melody instrument; at present, the Plectrum/Finger and Poly/Mono buttons are assignable to MIDI controllers. However, it would make ergonomic sense to have the option of selecting them via keyswitches.
So how are the patterns incorporated into the Melody instrument? They occupy the right-hand side, with up to four patterns that can be allocated, each assigned to the red keyswitches. The Melody instrument on the left plays by default — patterns trigger only when one of their keyswitches is held down; on releasing the keyswitch, the Melody guitar takes priority again. This behaviour can be reversed so that patterns are the default playing mode, with the Melody articulations being accessed via momentary keyswitches. I found this way round much easier to manage when combining patterns and melodies together. Although there are only four slots for patterns due to available space on the GUI, they are nevertheless identical in features to those in the pattern-based NKI, but with one exception — there are no 'ending chord' keyswitches, so these must be played manually following a swift keyswitch to Melody mode.
The Picked Acoustic library was recorded with three stereo mic setups. Condenser (AB) uses two spaced condenser microphones for a natural sound; Dynamic (MS) uses a single vintage dynamic microphone combined with a tube condenser mic in figure-of-eight setting for what the manual describes as an 'earthy' sound, and a pair of softer-toned Ribbon (Blumlein) mics. These are selected one at a time — they cannot be combined.
A Doubling feature creates the very attractive effect of two guitars spread across the stereo field; stereo spread is further enhanced (or diminished) by the Stereo Width control. Fret noise volume is also adjustable. On the Melody instrument, velocity response of the Open, Muted and Flageolet articulations can be compressed to smooth out the dynamic range, and the overall 'in-tuneness' of the guitar is adjustable from 'precise' to 'sloppy', a nice touch which, when set to around 20 percent, adds an agreeable and realistic amount of imperfection. High detune settings are best reserved for drunken open mic nights in dodgy pubs.
The Effects tab offers seven slots into which a predetermined selection of 13 Kontakt effects can be inserted. These include modulation, reverbs, delay, EQs and compression. Some effects from Kontakt's arsenal are notably absent — amp sims and distortion effects, for example — so presumably the designers only included those they felt most appropriate. The selection is highlighted by Kontakt's excellent new Replica delay and a choice of convolution reverb and the new Hall, Room and Plate reverbs. Effects can be edited, arranged in any order and saved as Sound Presets.
Although there may be a certain stigma attached to anything involving automatic accompaniment, I have to applaud Messrs Dalferth and Sholz for making this a creative tool rather than a constraining one. The patterns are surprisingly flexible, particularly with regard to harmonic content, and there's always the option to play ad-lib phrases on the Melody instrument when the occasion demands something more spontaneous. The sound is also an appealing factor — many would struggle to record an acoustic guitar as well as this without access to a top-quality instrument, expensive microphones and high-end audio converters, not to mention the right recording environment. Even if you have the keyboard chops to play convincing virtual guitar parts, PA offers a seductive alternative that sounds good and stimulates ideas, which can only be a good thing.
Companies such as Musiclab, Ample Sound, Vir2, Orange Tree and Indiginus also offer a range of fine-sounding virtual acoustic guitars that apply their own particular methods to accommodate strumming, picking and solo/freestyle playing styles.
- A beautifully recorded vintage Martin 00-21 steel-string played with fingers or plectrum.
- Patterns can have complete harmonic freedom using the 'As Played' voicing option.
- Flexible effects system benefits from Kontakt's new Reverbs and Replica delay.
- Melody instrument lets you play exactly what you want.
- A keyswitchable option for Melody instrument's Mono/Poly and Plectrum/Finger controls would be more ergonomic and convenient.
- The three-semitone slide-ins sound musically awkward.
Combining a wide range of patterns capable of free harmonic movement together with a playable and expressive instrument, Picked Acoustic throws off the shackles to reveal a creative and inspirational tool for songwriters, keyboardists and — dare I say it — possibly even some guitarists who might be wooed by its audio quality.