Create new content of a different type within the article edit screen?
The Inline Entity Form should help assuming the content types need to reference each other as well!


  Provides a widget for inline management (creation, modification,
  removal) of referenced entities. The primary use case is the parent ->
  children one (product display -> products, order -> line items, etc.),
  where the child entities are never managed outside the parent form.


It was created primarily for Drupal Commerce (Product display -> Product references on one page), but the functionality is there for other entities (out of the box it supports nodes, so it should be fine for your needs).

(Assumed) use case:


Add an entity reference for Songs onto an Album content type
Configure the entity reference to use the inline entity form (IEF) as its widget
Add an album - from here you can add songs to the album using the IEF
When you save the Album, it'll create the Album node plus all of the Song nodes and keep an Album->Song reference