To get this achievement all you have to do is choose the right inspirations in whatever order. Due to its difficulty the developers chose to give us a hint in form of a poem. In this guide I'll clarify what every line refers to and then do a walkthrough to explain what you really have to do to get it, just remeber that the bold words are the necessary steps to do, in order to progress the storyline while the bold and underlined ones are necessary to get this achievement:

"A portrait drawn in different style,
Use the sketched portrait that can be found in the locked closet on the 3rd day as an inspiration

a push through sleep, just for a while,
Push through sleep at the end of the 3rd day

the sound of rain does make you smile.
Use the rainstorm on the 4th day as an inspiration

Behind those bars, trapped with a hiss,
Use the book of poetry which tells you about a trapped panther as an inspiration

a call, so strange, yet full of bliss,
you might regret a second miss.
On the 2nd day when Leos calls over you have to answer the phone

My latest piece, in one fair letter,
Use the letters as an inspiration

while clouds rush on a change of weather,
Use the clouds/rain outside the cottage as an inspiration

transform its state and make it better.
Use the book "Everything Changes" as an inspiration

Worth your while, if you don't mind,
these tiny things, so hard to find?
Now back to play, please be so kind!"
A final message from the developer to everyone that would try to get it.

After the introduction, that ends after the first nightmare, where Wilma and Arthur lay in bed toghether, you have to pick one inspiration object which will be the poetry book.

Next you'll hear a terrible screeching sound and you'll have to click on the beams to the right side of the room, on the lantern and on sky and storm/rain outside the cottage

The phone will be ringing, but you'll be able to obtain one last inspiration before picking it up, which will be the book Everything Changes.

Now you have to answer Leos' telephone call.

After the second nightmare, where Wilma is stuck in a well, you'll hear a tic toc that won't let you progress. What you have to do is click on the locked closet, then the flowers outside the cottage. Open the closet and click once on the clock.

Now you'll be able to add three more inspirations to the composition which will be: the sketch, inside the closet, on top of the clock, the letters and the sky and storm/rain outside the cabin.

When asked, try to stay awake.

After the third nightmare where Wilma is speaking at the telephone to herself, she will hear whispers that won't let you progress again, all you have to do is to call Leos at 1255.

Now for the two final inspirations click on the rainstorm that hits the window and on Wilma herself.

Regardless of what you choose afterwards you'll unlock "A Concert for the Ages" anyway when Wilma bows at the cheering audience.