The No-Synths-used, Synthesizer-sounding track: This track is a bit of an experiment, I tried to make a "synth" track using no actual synthesizers.  
Its just a rough demo to see if it was possible to make something genuinely sounding like real synthesizers on guitars, using synth effect pedal(s) as opposed to a slightly synth-esque guitar track,

Therefore, there were no synthesizers used to make this track, simply an electric guitar and a bass and effects pedals, admittedly the main one used is a Synthesizer effect pedal...

So, I'm using a new synth effect pedal from BOSS; the SY-1 which costs £175 - a new low price-point for guitar-synth technology. It is literally a guitar pedal there is no special pickup for the guitar or bass and no MIDI conversion, it simply seems to process guitars and basses to make them sound like synthesizers (and organs) - even polyphonic ones.

This track uses the BOSS SY-1 pedal with a bass to create the bass  register sequence and also with a guitar to create a string synth sound in the higher registers. 
One negative about the SY-1 pedal was its monophonic output - I basically expected it to be stereo.
Thoughts on the pedal:-
Whilst this pedal has 121 usable synth sounds in 8 categories it has the following issues:

1. Mono output (not much use for most synth sounds needs a stereo effects pedal to bring it out).
2. Fiddly little knobs, which are small and close together and some are concentric dual-function items.
3. No display whatsoever, so you can't see the name, number or type of an effect.
4. No scroll forward or backward buttons.
Basically, it seems to me to be usable only as a desktop effects unit I can't see how you could use it in a band unless you only wanted to use one sound there is no way you could change patches in a live scenario.
Having said that, the sounds are good and relatively convincing and varied and polyphonic, so its not all bad.

I intended to do a lead-synth solo on the SY-1 with the guitar, but couldn't get a nice sound that could be heard over the sonic thickness of the existing bass sequence and string pad, so simply played a distorted metal type of jam/solo, which although now meaning the track doesn't sound like its made 100% on synths it still doesn't contain an actual synth.

The SY-1 pedal has a number of other sounds such as Organs, Pads, Leads, Basses and Sfx sounds - its great if you have the means to convert the output to stereo - I used a Zoom MS70CDR pedal. 

In future I will use the pedal more sparingly as garnish or an option rather than for the entire track.
NOTE: My BOSS GT001 multi pedal does some synth sounds as does my GT01B bass pedal, so I could also have used those. They are more limited in synth patch count, but are stereo...

1. DRUMS: Behringer RD-1 
2. BASS-synth Sequence effect sound: Ibanez Soundgear SG300 Bass Guitar thru BOSS SY-1 pedal on a sequence setting and Zoom MS70CDR for the stereo sound and reverb.
3. String Synth effect sound: Ibanez RG370 6 string guitar thru BOSS SY-1 pedal on one of the string synth settings, plus MS70CDR again.
4. Lead guitar: Ibanez RG370 (again) thru BOSS-GT001 multi effects processor.

Synthesizers Not Allowed (SY-1 guitar pedal)

South West UK based, amateur, solo-artist, creating tracks with (mostly) analog synthesizers, analog drum machines, electric bass and guitars.
The tracks are instrumental music pieces and "jams" in a variety of styles, from pop to rock, 80s, electronica, funk/jazz funk, fusion and prog - often heavily stylized and influenced by artists from the 70s and 80s.

Originally from the West Midlands, I now live in North Somerset, near Bristol 
 
ANALOG MONOSYNTHS: Arp Odyssey Rev 3, Behringer Model D, Behringer Neutron, Behringer K-2, Behringer Crave, DSI Mopho SE, Arturia MiniBrute SE, Novation Bass Station 2, KORG Volca Keys, Waldorf Rocket.
ANALOG/HYBRID POLYSYNTHS: Sequential Prophet REV-2, KORG Prologue, Novation Peak, Roland JD-XA, KORG Minilogue, Behringer Deepmind 6,MFB Synth Pro, Dreadbox Nymphes.
DIGITAL SYNTHS: Yamaha MODX7, KORG Modwave, Waldorf Streichfett (string emulator), Roland D-05, Modal Argon8, Modal Skulpt, Novation Mininova, Yamaha DX100 and KORG Volca FM.
DRUM MACHINES: Arturia Drumbrute & Drumbrute Impact, IK Multimedia UNO Drum, Behringer RD-8 (808), Alesis SR16.
GROOVEBOX: Elektron Model: Cycles.
SEQUENCERS: Arturia Beatstep Pro, Arturia Keystep.
CONTROLLERS: Impulse 61, Launch Pad Pro, Launch Keys 49, Keith McMillen K Board Pro 4, Expressive E Touche.  
 
Influences:  Ultravox, Vangelis, Nile Rodgers, Peter Gabriel, David Bowie, Chic, Jean Michel Jarre, Gary Numan, Wendy Carlos,Tangerine Dream,  Stevie Wonder, Steve Vai, Joe Satriani, Red Hot Chili Peppers, Stanley Clarke, Marcus Miller, Level 42, Duran Duran, Talk Talk, OMD,A-ha, Howard Jones,The Stranglers, Scritti Politti and Classical music, especially Bach, Beethoven, Shostakovich and Tchaikovsky.

Synthesizers Not Allowed (SY-1 guitar pedal)

Sonic Microcosm