It received mixed reviews upon its release today in history, January 12, 1968, but is today heralded as "unlike anything else" (Rolling Stone magazine) and is regarded as one of the greatest albums of all time (ranking 29 in Rolling Stone's poll of 500 albums).

The LP is none other Led Zeppelin, the eponymous debut by guitar god and former Yardbird Jimmy Page and his band of 'super musicians': John Paul Jones (bass), John Bonham (drums) and Robert Plant (vocals).

Considering Led Zeppelin's legacy today, it's surprising that the band struggled to find favour in the 1960s-'70s climate of much-hyped rock 'super groups'... At least among the press. Among the public, the band had no trouble building up a large and devoted army of fans and groupies.

Many strings to his $4,200 bow: guitarist Jimmy Page

Within a few years, Led Zeppelin had become the #1 band in the US and, though it is often forgotten, their commercial success for a period rivalled The Beatles. Since their split - following the accidental death of John Bonham in 1980 - the band have sold more than_300_million albums worldwide.

So what does this mean for collectors? Well, whether it's Led Zeppelin, The Beatles or The Rolling Stones, the legacies of classic rock bands endure especially strongly. This was demonstrated in 2009 when Led Zeppelin reformed for a one-off gig at London's O2 arena.

The concert now holds the world record for the "Highest Demand for Tickets for One Music Concert" as 20 million requests for the reunion show were rendered online. Proof, if any were needed, that droves of people still want a part of Led Zeppelin's legacy - and are willing to invest their cash into it.

This has translated to the auction block, like at memorabilia specialist Julien's Autumn_200_5 sale when a violin bow used by Jimmy Page to play his guitar in concert sold for $4,200. And, last year, Paul Fraser Collectibles sold a set of four Led Zeppelin signatures - including the late John Bonham - for $8,170.

But the great news is that you don't need to spend thousands to invest in Led Zeppelin. Jimmy Page's signature, for instance, is for sale on the market priced at a relatively-small three figures - an investment which can be reinforced by buying the other Led Zeppelin members' signatures to build a portfolio in the future.