mass_dl_url.sh

# -n# [xargs arg] for number of arguments to process at a time from the piped 
#    (file in this case, each line of file is a separate URL, so -n1 means 
#    treat each line as a separate argument)
# -P# [xargs arg] for number of parallel processes of command to run at a time,
#    (in this case just run 2 at a time)
# -L [curl arg] instructs curl to follow redirects
# -O [curl arg] instructs curl to output the file using the name from the input
#    arg

xargs -n1 -P2 curl -L -O < manifest.m3u
# or `manifest.m3u | xargs -n1 -P2 curl -L -O`

# loop for converting files from aiff -> alac
for file in *.aiff; do ffmpeg -i "$file" -vn -c:a alac -f ipod "${file%aiff}m4a"; done