Can you define psychedelica? Behind punk, it’s probably the most over-used term in the musical genre lexicon. That won’t change with this sprawling two-disc exploration of Australian psych, past and present.

Mixing ‘60s and ‘70s tracks with contemporary ones is an approach that could have gone horribly wrong.The wonder of this is how well the old tracks blend seamlessly with the new. Compilers Gaz Cobain (aka The Amorphous Androgynous) and Brian Dougans have done a splendid job of unearthing lost, forgotten and current nuggets and the mastering is great. It’s the fourth edition in a global series.

Here’s where you get some free advice: Listen without prejudice. Ignore the tracking order. Rip this to iTunes or insert both discs into a multi-disc player and hit random. It’s the best way to let it all soak in. Its a double CD package that's too wide-ranging to absorb proiperly in one hit. 

Doug Jerebine’s “Midnight Sun” shows the influence Hendrix had on anyone who was listening in Australia in the ‘60s. Heavy guitar and a vocal not dissimilar to Jimi’s makes this a stand-out. The heavy acid funk drive of Leong Lau’s “The Atlas Revolution” comes from a similar place with a twisting wah-wah guitar running right down its middle. The Malaysian-born Lau’s “Salem Abdullah” is trips but not in the same league.

If you thought his hit, “Winter in America”, was representative of singer-songwriter Doug Ashdown then “I’ve Come To Save Your World” will be an ear-opener with its folk-meets-prog mix of guitars and swirling keys. De-tuned harmonics make Pip Proud’s “A Fraying Space” one of the weirdest cuts here and confirm his status as a true musical outrider.

Contemporary bluesman Ash Grunwald’s “Walking” puts the heavy into blues rock. Fans may fear that Tame Impala have wandered off into the ether on their latest album but “It Is Not Meant To Be” is moody and moving in its understated intensity. Cyborton’s “Gods of Norse” dates from 1977 and flips the switch to progressive rock with wandering synth lines and strictured rhythms. Their second inclusion “Raga in Asia Minor” rides a swelling electronica track that moves them into Kraught rock/disco territory.

The strung-out sounding “Mercy Killing” by Melbourne’s Sunset Strip and shows off their penchant for Neil Youngesque guitar explorations that burn brightly. Tynaround’s “Colour Your Mind” dates from the same place and time and sets a high bar for the rest of the collection for guitar-centric psych rock.

That everything sits so well is a mark of how far back you can take modern recording techniques if you try. Tame Impala doesn’t sound out of place next to The Missing Links’ 50-year-old backward masking experiment “H’ Tuom Tuns” (spell it backwards) and is still a whacked-out tour de force.

Russell Morris’ “The Real Thing” from 1969 is often held up as the high water mark for Aussie psych and it leads the first disc. It’s actually one of the lesser tracks here when heard in context. Molly Meldrum’s lauded production job comes across as a missed opportunity rather than an unwitting work of genius. Even if he didn’t know what he was doing with all that multi-tracking you might wonder why he didn’t go for broke and push more sonic limits.

Madder Lake’s signature “12b Toothbrush” and “Matter of Time”, Railroad Gin’s best-known song, will be familiar to Australian ears. The eccentric Mandu had a distinctive voice and shows it off on his cover of “Gimme Shelter” but the arrangement comes across as a tad cheesy.

Kongress was (as far as I know) the only US band on this collection that was fronted by a practising magician from Australia in Geoffrey Crozier. “Eyes of the Witness” is bombastically trippy and compelling and recalls The Crazy World of Arthur Brown.