How I turned 7 classic metal songs into instrumental funk workouts

Having read the title of this article, a more pertinent question on your mind might be: why did you turn seven classic metal songs into instrumental funk workouts?

I don’t really have a response to that, other than: I don’t have much work on currently. Also, it’s not like it’s the weirdest thing to happen in 2020, so I think you should just get over it already. I’ve made an album of light R&B cover versions of heavy rock songs and that’s all I’m going to say about it.

Although, no. Sorry. I’m going to say quite a lot about it. That’s what this article’s all about, really.

Let’s get down to brass tacks. The album - IronWood - Metal Covers for the Funk Inclined - is available now on Bandcamp, and you can also pre-order it on vinyl.

IronWood - Metal Covers for the Funk Inclined: track-by-track with Rob J Madin

1. Metallica - The Call of Ktulu

The album opener is a cover of Metallica’s 1984 Ride The Lightning album closer. The original version is a frenetic multi-part instrumental nine-minute prog-rock epic, which my version is not.

The starting point of the album was to try and imagine what a 1960s funk rhythm section (à la The Meters or Booker T & the MGs) would sound like if, for some reason, they had to perform material by popular metal artists of the future. (Their future, not ours). I think this one is perhaps the most ‘Metersy’ of the lot.

A big step in the right direction was to just play the guitar riffs without any distortion. (For all the tracks, I used a Telecaster through Voxengo’s free Boogex amp plugin in Logic with some nice, warm tube-style EQ).

Another important step was to buy a “professional cowbell beater” off the internet. I’m embarrassed to admit that I’d previously been hitting my cowbells with a standard drumstick, like some idiot Neanderthal. Is there a perceptible difference in tone quality? Does striking a cowbell really necessitate a ribbed grip section? Was it worth the £6.99 plus postage? I’ll let you be the judge.

The original Metallica version of the track begins with a subtle, haunting guitar melody. I broke this down into three components - two guitar parts and one Rhodes, which I played staccato (very unsubtle and not haunting).

As James, Kirk, Lars and Cliff weren’t necessarily the funkiest lads of the mid-’80s, I had to introduce a fair bit of syncopation in the drums and bass throughout - and a hell of a lot of cowbell – but otherwise, I kept the arrangement relatively similar. I even managed to shave five minutes off the original running time. You’re welcome.

2. Korn - Blind

Between the ages of 13 and 16, I - rightly or wrongly - spent a huge chunk of my bounteous free time listening to nu-metal music. If you’re unfamiliar with the genre, where the hell were you between 1998 and 2001? But no. It’s a valid question. 

Nu-metal at its best was enormous downtuned guitar riffs, angsty shouty vocals and hip-hop influenced drum grooves; and at its worst was eyebrow piercings, creepy chin beards and toxic masculinity.

Korn were one of the first bands on the scene (Blind came out in 1994) and one of my personal faves back in the day. I even had an official Korn pencil case in year 9, if you can believe such a thing was commercially manufactured. 

Funkifying Korn - and all the other nu-metal bands, for that matter - was much easier, as they already have a big emphasis on syncopation and groove in their songwriting. I chose Blind, as I’d always thought the repeating diminished guitar chord at the start sounded a bit like a pitched-down, distorted Prince sample. I ended up speeding it up slightly and adding a wah guitar part, so the resulting intro sounds less like Prince and closer to the theme from Shaft, but it still works I think.

One fundamental element of metal that you might think would be tricky to replicate in a low-key, instrumental funk context is the deep, guttural shouting (or the ‘death growl’) of rock vocalists. Luckily you can achieve a very similar effect by overdriving the Hammond organ a little, and mashing all the low notes at once - a technique I used profusely throughout the album, and continue to use in any spare time I have.

3. Deftones - My Own Summer (Shove It)

1999 pop culture fans might recognise this song from the official soundtrack to The Matrix film (1999) or the official soundtrack to the Street Sk8er 2 PlayStation game (1999).

Deftones were always towards the more classy end of the nu-metal spectrum for some reason. Maybe because they’re a bit more experimental. Maybe because the lead singer is called Chino. Either way, My Own Summer (Shove It) is a certified banger and was already so funky that I didn’t really do much with the arrangement at all. It’s essentially a straight cover. To my knowledge, it’s the only funk tune in drop C# tuning.

One tweak I did make was in the post-chorus section, where the chord progression suddenly becomes major and it’s like the sun comes out momentarily. In the original version, the band manages to make this not at all cheesy. It’s a powerful and deeply satisfying chord change, but it doesn’t make you wonder whether you might have somehow switched over to Magic FM mid-song.

As far as I’m concerned this was a lost opportunity, and one that I have rectified in my version. I even threw in a lovely chord substitution the second time around, and liberally shook a tambourine throughout.

4. Slipknot - Duality

This was the first song I did for the album. Despite Slipknot, at one point, being my number one favourite band on the planet, by the time they released Duality in 2004 I had all but outgrown my metal phase (I later shrank back into it), so it completely passed me by until a few years ago.

The track is perfect for a funk revamp, mainly down to its syncopated main riff, catchy hooks, creative drum grooves, and surprisingly jazzy flourishes.

Slipknot have always placed a heavy emphasis on groove and melody. In fact, I recently discovered that some of their early demos (pre-Corey Taylor) actually incorporated elements of jazz, funk and disco. Swear down mate. Look up their Mate.Feed.Kill.Repeat. EP if you don’t believe me. 

In place of the distorted pinched harmonics in the main riff, I played major seventh chords on a Juno-106 synth, which gives it a bit of an ‘80s Cameo-esque flavour. There’s an electric piano that plays throughout (as well as an acoustic upright), which I put through the Izotope Vinyl free plugin with a very slight warp model, to give it a really subtle wooziness.

I didn’t want any of these tracks to sound too ‘clean’, so I used quite a lot of compression and tape-saturation effects to give the album a lo-fi feel. The Soundtoys Radiator plug-in was a go-to, recreating the vintage warmth and colour of the Altec 1567A.

(Yes, I had to Google what the Altec 1567A is. It’s a tube mixer from the ‘60s apparently).

5. Drowning Pool - Bodies

If you’ve ever been to a metal club night anywhere in the UK at any point since 2001, you will have heard this song. I can’t vouch for other countries, but I assume it’s the same all over the world. And it will remain so, every night for all eternity. Do Drowning Pool have other songs? I can only presume they do. There’s really no way to tell.

For such an iconic, highly-regarded metal anthem, there’s not actually that much in the way of melody going on. The main riff is based around just two notes; it doesn’t really modulate away from the root for the whole song; and there’s a lot of shouting and half-rapping and shouting. But it’s great.

I decided to keep the most distinctive vocal elements of the track (the whispering at the start; the counting in the pre-chorus), but as the main vocal hook (“Let the bodies hit the floor”) is such a catchy rhythmic motif, I opted to play it on the Latin-American percussion instrument and primary-school music cupboard staple, the güiro.

The Latin vibe worked well with the triplet-heavy pre-chorus as well, so I just added a load more percussion - a combination of live (cowbell, shaker) and virtual instrument plugins (agogô, congas).

As I recorded the whole album in my attic studio, which is in no way big enough to accommodate a drum kit or Hammond organ, I used quite a lot of virtual instruments (Steven Slate Drums 5, IK Hammond B-3X), but spent a long time attempting to make them sound as real as possible. Everything was played in live on a USB/MIDI keyboard (minus the guitars and bass) and I tried to use quantisation as sparingly as possible. Which was difficult.

6. Slayer - South of Heaven

My first introduction to Slayer was their 1998 album, Diabolus In Musica, which I subsequently learned was a bit of an anomaly in their catalogue. In the ‘80s and early ‘90s, they’d been all about the thrash, but with this album they experimented with a more groove metal sound, in response to the burgeoning nu-metal scene at the time. (Kerry King has since claimed that it’s his least favourite Slayer record; I maintain that it’s probably my favourite. So it’s swings and roundabouts). I was initially going to cover a track off this album, but instead decided to pick something more classic from their early oeuvre.

South of Heaven is from the 1988 album of the same name, and is one of the band’s more downtempo numbers. In fact, even though I’ve sped it up slightly, it’s still one of the most chilled-out tracks on the album - ironic, given that it’s a Slayer cover.

There are some really fast, intricate little guitar licks in the pre-chorus, which took me HOURS to master (my own fault for increasing the BPM, I guess). I’m fairly sure I only managed to play it correctly once or twice, so - full disclosure: I think I just copied and pasted it multiple times. Apologies to anyone that feels cheated.

7. System Of A Down - Chop Suey!

Finally we’ve reached the end of the line. This System Of A Down track might be the best-known song on the album (it reached #17 on the UK Singles Chart when it came out in 2001), so I tried to keep the arrangement and structure more or less the same.

The wah Clav at the start was inspired by The Meters’ Just Kissed My Baby. I even tried to emulate the reverb effect by panning the dry signal to the right, and the reverb to the left. It’s quite subtle and not actually that similar, so there’s a small chance you didn’t pick up on that very niche production reference.

The drum groove (or at least the general feel of it) was nicked from the Vulfpeck track, Daddy, He Got a Tesla. I’m a big fan of the Vulfpeck sound - the Goodhertz Vulf Compressor is probably my most frequently-used plug-in. As with the aforementioned Soundtoys Radiator, it has the option to introduce an artificial noise floor - recreating the circuit noise of a physical preamp and adding some warm vintage dirt to a mix. I use it on almost everything, in varying quantities.

Possibly my favourite part of this track (and maybe the album) is the half-time breakdown. In the original version, at the one-minute mark, the song dissolves into a dark, brooding, down-tempo section with emotive lyrics and impassioned vocals. In the funk version, it instead descends into a sort of sexy slow-jam. I originally had a DX7 electric piano, finger clicks and a bell tree in the mix, but I decided it was a bit too Boyz II Men - even for me.

It’s not like it’s some kind of novelty album.