Research & Development of soundtrack and sound effects

For my soundtrack I intend to use a mixture of ambient diegetic and low non-diegetic to create an atmospheric but natural feel, thus allowing a certain relatability and submersive effect. For example, i intend to feature the likes of sounds of birds, mild traffic etc for the diegetic and for the non-diegetic i intend to use the 'lunar strings' instrument on GarageBand for my non-diegetic.

Here is a scene shot example of the type of sound i wish to achieve using  GarageBand:

Here is a clip i uploaded to youtube in order to exemplify the sounds i wish to create: