The themes for this Saturday's X Factor semi-final are, as usual, boring: "songs to get you into the final" (well, duh) and "songs for you" (eh?). And every week, the show has a major problem with constantly sticking to very well known songs, for fear of alienating viewers – remember when Tulisa thought Respect by Aretha Franklin was a bit obscure?

We've decided to ignore that completely and choose the songs we want to hear the final four sing, with no Rihanna or Coldplay in sight. In a lot of cases, it involves a bit of a change of style…

JAHMENE DOUGLAS

Best performance so far: At Last by Etta James

What he should be singing: Working on a Building of Love by Chairmen of the Board

Why: Jahmene desperately needs to loosen his tail feather, stop standing stock-still and sing something with a bit of gumption. This 1971 Holland/Dozier/Holland stormer takes care of that, while giving Jahmene plenty of freaky high notes to hit, but without too much of his silly, difficult-poo wibbly stuff. It won't fall foul of his famous moral censorship either – it's about love for one's fellow man, as inspired by Bible teachings.

Alternatives:

1) The Quest by Bryn Christopher

Already sounds like a Jahmene Douglas record. It's frighteningly modern by his standards – 2008! – but has an old-school soul feel.

2) Cold War by Janelle Monae

A soul song, but uptempo, contemporary and with a bit of steel.

3) It's Your Thing by The Isley Bros

Get the funk, Jahmene. Get the funk! The shafunk. The jahfunk. Get that.

JAMES ARTHUR

Best performance so far: Sweet Dreams by Eurythmics

What he should be singing: The Beautiful Ones by Prince

Why: Despite his successful cover of Let's Get It On, and tabloid reports that James is on the verge of having to set up some kind of roster to cope with the groupies flooding his hotel room, his voice and tear-jerking back story make him much more suited to slightly angry songs about loves lost. This one would obviously need to be taken down an octave, but it has a great screamy finish.

Alternatives:

1) Hang Me Up to Dry by Cold War Kids

Cool, slightly threatening, with a throat-shredding chorus. To be played solo with choppy, stop/start acoustic guitar. 

2) The Bones of You by Elbow

A not-overplayed song by a band popular with the segment of the audience James needs to attract: people who normally don't deign to vote.

3) Strange and Beautiful by Aqualung

Perfect for James, albeit maybe a bit on-the-nose and well-known.

CHRISTOPHER MALONEY

Best performance so far: Waiting for a Star to Fall by Boy Meets Girl

What he should be singing: Ferry Cross the Mersey by Gerry and the Pacemakers

Why: Christopher's chances of winning – and let's not be complacent here, Christopher very much could win The X Factor – rest on him being the only contestant with a strong regional identity. Christopher needs to play on that mercilessly. Alternatively, he should focus on pleasing his other core support: nans. This song does both, horribly well. Be afraid if he sings this.

Alternatives:

1) I Should Have Known Better by Jim Diamond

Lachrymose, tremulous, cheesy, basically bloody awful: it's Christopher!

2) Miss You Nights by Cliff Richard

It's slow and quite easy to sing, with plenty of opportunity for the Maloney vibrato and buckets of Nan-appeal, but it's also actually, secretly a brilliant song.

3) Danny Boy

Nans.

UNION J

Best performance so far: Call Me Maybe by Carly Rae Jepsen

What they should be singing: Borderline by Madonna

Why: Union J are by far the most difficult to pick for, because they barely have any identity at the moment. They need to be much more fun and – why not? – a bit camper. A bit of Rylan style. Lose the clothing-catalogue stares and the leather jackets, get some colour on and do some early Madonna. Any 80s single will do, but Borderline's the best one so let's go with that.

Alternatives:

1) Need You Now by Lady Antebellum

Massacred by Carolynne Poole at judges' houses, but this ought to be a big X Factor song.

2) Long After Tonight Is All Over by Jimmy Radcliffe

If the Nionj insist on sticking with ballads, at least do a great one: this Northern Soul end-of-the-night classic would get their girl fans all warm and gooey and ready to ring a premium-rate phone line repeatedly.

3) Undercover of the Night by The Rolling Stones

Look, we're trying anything now but: the Stones are everywhere at the moment and we can see Union J having a crack at something from the hand-clapping, peacocking-around-the-stage disco era. It's po-faced but silly, which would suit the boys. George could pretend to play guitar. Actually, we're coming round to this. Lads! You've got nothing to lose!

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With thanks to Talia, Simon and Siobhan