The album features Ken Freeman on synthesisers, who started with a Minimoog and ARP Odyssey. Later in production, a Yamaha CS-80 was brought in which was used to re-record various overdubs, including the horns. Freeman was able to create various sound effects from scratch, including a military drum sound on "The Artilleryman and the Fighting Machine". Among the synthesisers used was the Thunderchild SZ3540, a custom made monophonic model built by JWM Electronics after Wayne sought for a fatter, bassy sound. Wayne wanted to create the Martian war-cry of "ooll-la" (which they chant before destroying their foes with their heat-rays) with a synthesiser, but he and Freeman could only create sounds that resemble "ooo" and "ahhh" and not the "l". The final effect was achieved with a multitrack "voicebox guitar effect" devised and voiced by Jo Partridge, who plays guitar on the album and made the sound "as dramatic as possible." (Partridge is consequently credited on the record as "the Heat Ray".) All but one of the foley sound effects heard on the record were created by Wayne's wife Geraldine. Wayne said the one that he is asked about the most is the sound of the cylinder unscrewing when the Martians emerge from their spaceship, which he achieved by turning and scraping two kitchen saucepans together that Young then amplified and captured in stereo. Most of the musicians on the album had also played on Essex's debut studio album Rock On (1973). Wayne wrote out the various parts of the score for the band, which was performed live in the studio without any click tracks, leaving the group "to groove together, and then move onto the next tune." It took one week to record almost an entire side of the album. The string section consisted of violins, violas, cellos, and double basses, totalling 50 players and led by violinist Patrick Halling. It was recorded in the course of two evenings at Abbey Road Studios.
the aLbum featurES kEN FrEeman On syntheSisErS, who Started WitH A Minimoog and aRP OdYssey. laTER In PRodUction, a YAMahA cs-80 was broUGht in which Was used To RE-ReCord VARious oveRDUbs, IncludiNG the HorNS. FrEEmAn wAS able TO create varioUs sOund efFeCts fRom ScRatch, includIng a militarY dRum sOuND on "the ArtilLerYMAn AnD tHE fightInG MachIne". among THE synthesiSErs useD waS the thunDERchILD sZ3540, a cuStom made mONOPHoniC ModEl BuIlt by jWm elecTronicS afTEr wayne soUght For a fatTer, BasSy souND. wAYnE wanted to cReAte the MARtiAn waR-CrY Of "ooll-La" (wHiCh tHEy CHant Before DestroYinG Their fOes with THeIR hEAT-rays) witH a syNtheSiSer, BuT he AND freEMan cOulD onlY create sOUnds thAt REseMble "ooO" aNd "ahhh" aND not THe "L". tHe Final effect wAs achieved wiTH a mUltITRaCk "vOIcebox guiTaR effECt" dEvIsed anD voiCed by jO ParTridge, who plaYS guitar on ThE album ANd MaDe THE SOUNd "as dRamatic AS pOsSiBle." (paRtrIDge Is conSEqUENtly CrediteD on the recORd aS "tHe heAt rAy".) AlL but oNe oF thE fOley souNd EfFEcts HeArd oN thE RecoRD were CrEaTED By WAyne'S wIfe geRAldIne. wAYNe saId tHe One thaT He is ASked aBOUT tHe mOST Is The SOUnD oF the cyLinder unScREwinG WheN the martiANs emErgE froM theiR spaCESHiP, whicH he aChiEvEd by turning anD scrAping tWo kitcheN saucepans toGEthER THat yOung THEN ampLifIed aNd capTured In sTereo. moST oF the MusIcIAns oN The album HaD AlsO played On ESsex'S DebUt StudIo aLbUm RoCK oN (1973). Wayne Wrote oUt thE varioUS parts Of thE sCoRe foR tHe BanD, WhiCh waS peRFoRmed LiVe In thE StudIo witHOut any CLiCk Tracks, lEaVINg the gROUP "tO GRoove tOgeTheR, aND thEn move OnTo tHe nEXT tune." it tOOk one Week to RecoRd aLMost An entIrE siDE of the alBUm. THe strinG secTion consiStED Of vioLInS, vIolas, CElLos, aND doubLe bassEs, TotaLlINg 50 players and Led By vIolInist paTrIck hAlling. It wAs RecoRded IN The cOursE of tWo EvENings at aBbey road stUDIos.