From your description, I understand you are looking for album/singles artwork for 30 songs, based on 30 abstract pieced of art that you have & retouching the background of 20 more.
I have 15 years of experience in band/musician/artist identity, branding & graphic design. I've worked with musicians/bands/artists of all genre's & notoriety including Kill Hannah & Jay & the Americans. Most recently I've done branding for New York's Uninvited guests, & created logos for Skeleton Quay (Australia) & Sleepwalking Home (Utah). Likewise, I also created a poster for a blues music event at the famous BB King Blues Club. SimilarlyI have 6 years experience in photoshop image retouching. I believe I am the right person for your project as well.
I propose to create arworks for you for $ 555 USD in 10 days. After finding out your suggestions and inspirations, I would start by getting a sense of any ideas you have or brainstorming. Then I would sketch out a mock up. After agreeing on the mock up I'll start rendering the designs in Illustrator so it can be easily resized and/or photoshop so it can be exported to all your needs. The final steps would be adding fine details, effects and touches and color correction. After 10 days, small, simple revisions are no extra cost, but any additional complex or timely work/revisions/charges can be negotiated as tasks using the proposed milestones function at the rate of $33.33 usd/hour.
Please contact me to discuss further details.