The Horrible Histories TV programme had a song that explained the viewpoint of both sides:

The English Civil War Song

We are the Roundheads, we don’t want kings no more,
That’s why we started the English civil war.
People say we’re no fun, but we disagree,
Especially when explaining, parliamentary democracy.
We are particularly excited by the notions of jurisprudence…

That’s enough dullness, we’re the Cavalier crew,
Supporting King Charles, & everything that he’ll do.
Puritans bore us, it’s really a crime,
When your parliamentary business cuts our partying time.

Roundheads, soundheads, keep the music down heads,
Rules and regulations led, dull but fair.
Cavaliers three cheers, wackier head gears,
We love to boogie with our peers. Unfair? Don’t care!

I am the king, I can do what I like,
Start up a war, or a big tax hike.
Got a French wife, she’s a Catholic.

O law!
Really, King Charles, we’re not quite sure!

Insolence! Is that how you talk to the Crown,
I am the King, I’ll just close Parliament down.

I’ll think you find, that’s in breach of due process.
Here’s what we say to that (spit) Now clear up this mess!

Roundheads, soundheads, witches should be drowned heads,
Don’t believe in crowned heads, Parliament’s our thing.
Cavaliers three cheers, your superiors,
We’re all toffs who cry ‘Here, Here’ & ‘God Save The King’.
(That’s me!)

Fight! Fight! Fight! Fight! Fight! Fight! Fight! Fight!

Cavaliers! Roundheads! The English Civil War!
Why is it called ‘civil’? May I kill you, please? Sure!

Love civil wars, to be fought on this land,
If I get to power, Christmas will be banned.

No chance Cromwell, victory will be mine,
You’ll never pass a ban on mince pies & mulled wine.

That’s what you think, just wait ’til you’re caught,
I’ll also scrap theatre, music & sport.
Your pathetic war will finish even before it’s begun,
We’ve taken Charles prisoner, the Roundheads have won!

(Oh!)

Victory three cheers, Cavaliers in tears,
No power for years, I’m the leader of the pack!
Charles head Roundhead, hurrah now the king’s dead,
Sins binned, instead a righteous track

(But we’ll be back!)

LFF

PS They also did one about Charles II - the video is on YouTube:

Charles II