accept multiple -p=STRING for chord

src/main.rs

@@ -7,15 +7,17 @@ mod tone;
 
 fn main() {
     let flags = flags::Flags::new();
+    if flags.debug {
+        eprintln!("{:?}", flags);
+    }
 
     let mut syn_seq = seq::new_syn(syn::Syn::new(
         flags.debug,
         flags.sound_font,
         flags.sample_rate,
     ));
-    syn_seq.append(1, "3c1");
-    if let Some(play) = flags.play {
-        syn_seq.append(0, play);
+    for i in 0..flags.play.len() {
+        syn_seq.append(i as i32, flags.play[i].clone());
     }
 
     play(syn_seq, flags.sample_rate, flags.bpm);