Even if Music 2 scales higher than most subjects, it's a demanding subject (from what I've heard), you would generally only pick the subject if you have a passion for music, playing it, listening to music, remembering all the steps, notes and chords is a lot more difficult than it seems (which I never really understood because creative subjects require, well creativity, passion, hours of practising yet the scaling isn't that high???)
As for History Extension, you would too only pick this subject if you enjoy history, (in saying that Hist Ext is a lot different to modern and ancient lol, you don't actually learn about history, you learn about historiography, which is the like the history of history and the influence of context on the construction of history, I'm probably making it sound like a yawn fest but trust it's actually interesting if you enjoy why historians write the way that they do)
Remember OP, scaling doesn't mean jack unless you do well!!!