Hi, I know it’s still relatively early to be posting this kind of thing as I am a rising junior, but after browsing through countless threads my curiosity got the better of me 
I believe have an idea of what I need to do to improve objectively (GPA/SAT/rank), so I would especially appreciate any feedback as to how my ECs would fare in selective admissions as I am genuinely passionate about all of them. 
I understand that it is difficult for anyone to speculate (especially without official SAT scores), but thanks in advance for any constructive advice!
GPA: UW: 3.9 , W: 4.3
Rank: 9/400+
IB Diploma Candidate
Courseload: most rigorous for my school
ECs: (please note that the number of years listed will be what I have completed upon senior year)
-Classically Trained Pianist (12 years)
-won a few national awards/competitions, compose music
-Symphonic/Honors Band (7 years)
-alternate for District Band, 1st chair oboist
-Small family farm (10 years)
-collaborate with local community garden (won’t go into too much detail for privacy reasons), coordinate events
-Humanitarian Club (3 years)
-Founder/Co-pres, fundraise for UNICEF, sign petitions, create PSAs advocating for
international human rights
-Beta Club (3 years)
-elected VP for next year
-Drama Club (5 years)
-Treasurer, one lead role
-Church Youth Ministry (6 years)
-lots of volunteer hours/service trips, music instructor at Vacation Bible School, Peer Minister (leadership role)
next year, director/spokesperson of fundraiser that I started
-Varsity Swim Team (4 years?)
-average swimmer, no recruitment possibility, might quit next year to make time for IB and other ECs
-other generic honor societies and NHS inductee (2-3 years)
Summer Activities:
-Intern at music therapy research center: perform for patients and assist in conducting research
(will continue volunteering year round)
-Intern at international public health nonprofit (also will continue year round)
-Church mission trips and VBS
Awards/Distinctions:
Nothing major as of yet, save for the few piano awards as mentioned above.
consecutive Superintendent’s Honor Roll, Presidential Academic Achievement, generic stuff
for being in the Top 10% at my school
Received 2 honors certificates for online courses from Harvard University (both on public health related topics)
Hopefully my ECs adequately reflect my passion for public health/medicine and music as I believe they are the core theme of my app. My top reach schools include Stanford, JHU, Duke, Harvard, and Brown. Also plan to apply to Cornell’s Human Ecology school, but have heard the acceptance rate is significantly lower. However, I understand that I am far from a shoe-in at any of these schools and my chances are probably low as it is, so any particular advice as to how else I can enhance my app/stand out? I know for sure that I’m going to devote a lot of time and effort to writing those essays next summer!
Sorry for the long post, please let me know what I can do to improve!